Java Tutorial from Basic to Advanced in 10 Hours

Java Tutorial from Basic to Advanced in 10 Hours


what’s going on everybody it’s Bucky and welcome
to your very first java tutorial now in this order before we begin writing any programs
we first need to download something called the JDK and for all you new Java developers
out there this is the program that lets you actually write Java and actually compile it
and compile it just means a transferring it from code you can understand the code the
computer can understand so just follow me and by the end you’ll be able to write Java
code so the first thing I need you to do is go ahead and open up your internet browser
right here and once you have that open I’m going to use fire fact Firefox go ahead and
go to the website Java dot sun.com and this is gonna give you give you Javas main page
what you want to look for is the download link and this is gonna give you a bunch of
different Java editions to download you’re gonna want to go to the Java SE link and this
stands for a Java standard edition so go ahead and click that and what we’re looking for
is something called the JDK in this stands for Java development kit so we can write in
a well compiled Java programs now we just want the top one which is a standard one on
this EE stands for Enterprise Edition this and that beans is something else we don’t
want that so just go ahead and find the standard basic Edition and click download and once
you click that it’s replicant bring its a new page let’s see and yep and it’s gonna
say Windows which we want English which we want go ahead and agree and press continue
I already have this downloaded so I’m not going to download it again though just be
stupid but once you download it is gonna give you an executable file now um your executable
file is going to look something like one of these this is something else I downloaded
but it’s gonna give you a file like this called e x e once you get that file go ahead and
double click this and that’s going to start the wizard to download the JDK now it also
might give you a file on your desktop right here like put it somewhere right here if it’s
right there Jan just double click that and once you do a Wizards are gonna pop up and
you’re probably gonna have to click like next 40 times and press I agree I agree to some
stuff next next but once that’s all done then you’re gonna have the Java compiler downloaded
now let me show you guys what the Java compiler is if you go to your Start menu then press
CMD and press Enter your command prompt is going to come up now what this allows you
to do is have access to your java compiler and again like I said before to duck the Java
compiler allows you to transfer code that you can understand to code the computer can
understand and that’s what we just downloaded so let’s test it out Java C press Enter nothing’s
working and nothing’s working because the Java compiler it has it downloaded but whenever
you try to use it it doesn’t know where it is so let me show you guys how to do that
and again pay very close attention to this hopefully you downloaded it with all the default
settings if you didn’t then while you’re still gonna be able to see what’s going on but go
ahead and in your Start menu click on computer now go ahead and click the local disk witch
or whatever your main hard drive is then go ahead and click program files now you should
have a folder called Java go ahead and click that now go ahead and click the Virgin JDK
if you don’t see this that means you didn’t download it right so go ahead and click that
JDK the next thing in last thing I want you guys to do is click on the thing that says
bin right here and remember you follow all these instructions very carefully next right
click on any of these things right here just click on your topmost run remember right click
it and click properties now this is where you’re going to tell Java to look for your
compiler so it says location go ahead and copy all of location right clicking be it
it should say something like C program files Java your version and say been the last thing
make sure you get that bin that’s very important if you’re not if you don’t see it then do
this tutorial again and do exactly as I say anyways you want to see that bin so once you
have this golden code that’s what we’re looking for go ahead and X out of that now that’s
where you the compiler is so how do we tell your computer to look there well go ahead
and go ahead to click on my computer again from your Start menu and click properties
remember you want to right click it and click properties all these are very important go
ahead and click advanced system settings and probably a little message is going to pop
up if my computer is not freezing and it is so my computer properties advanced system
settings there we go continue and you’re gonna see something in your system properties called
environment and variables go ahead and click that and pay attention what I’m gonna do here
what we want to do is create a new user variable so go ahead and click a new now the variable
name for this you have to write pass PA th and the variable value is going to right where
that compiler is remember that link with a bin so that’s why it’s really important that
you get that link now go ahead and click OK and bam click OK on this ok and you now have
your compiler setup and ready to run so go ahead and go back to your command line and
in command line go ahead and type Java sea and unlike before we now have a bunch of crap
that pops up and this crap means that our compiler is ready and set and ready to go
so now with that being said we know that we are now able to write Java programs so in
the next tutorial I’ll show you guys how to do that but for now just follow this tutorial
that’s how you install a Java on your computer so you can actually write Java programs if
you didn’t follow those instructions exactly like I said you’re not going to be able to
write Java programs on your computer so make sure follow this tutorial very carefully do
exactly as I did I know it’s kind of a pain in the butt but it’ll be worth it in the long
run so um thank you guys for watching make sure you get a job in salt if you have any
questions or I wasn’t clear on anything just send me a message or leave a comment and hopefully
I’ll get back to you so again thank you guys for watching hopefully you have Java installed
and in next tutorial I’ll show you guys how to write our first Java program so thank you
don’t forget to subscribe to my channel and I’ll see you in the next tutorial what’s up
everyone its Bucky welcome to your second Java tutorial and in this tutorial I’m gonna
be teaching you how to run a Java program now I’m not gonna be teaching a lot of the
syntax about what’s in a Java program before we do that we actually needed to know how
to run one so pretty much you’re just gonna be copying me write a simple program and then
you’re gonna be learning how to run it so I’m go ahead and open any editor I’m gonna
open notepad plus plus just because it’s my favorite one and uh go ahead and the first
thing you want to do is go to file save as and we want to save this and remember whatever
location I already made a file on my right off my hard drive in there I have a folder
called test and I’m gonna save this as let’s save it as YouTube YouTube da and of course
that Java is very important and don’t forget where you’re saving this this is also important
so now we have a file called anything dot job but mine’s called YouTube Java now I’m
pretty much just going to show you a simple hello world program again in this story I’m
not gonna showing you like how to write Java I’m just be showing you how to run it and
then the next couple tutorials I’ll show you what everything means in it but for um beginners
just follow me the first thing you need to write is a class now a class in Java pretty
much in Java everything begins with a class and if you don’t have a class you can’t do
anything so you can’t do anything until you create a class so I’m gonna go ahead and make
a class called apples and in that class we’re gonna have something called a method now again
you don’t really need to know any of this stuff I’m just making a simple program I’m
just talking you along you’ll understand what all this means later but for now just stick
with me now in your class you’re gonna have something called a method now a method is
pretty much a list of things to do and this method is going to be inside the class now
the first thing your computer does is whenever it runs a Java program and looks for a method
called main so let’s go ahead and create that and you did this by clicking public static
void main and all of these actually mean something but uh again don’t worry about it for now
I promise you’re understand then in your parameter type of string args arg s and put empty square
brackets and uh i don’t know if i can copy this code in my description or not but if
I can’t I’ll put it in my description but I got a feeling YouTube’s not gonna let me
put code in for security reasons next after in your method you’re gonna want to have to
put um a statement or instruction about what you want your computer to do so go ahead and
write system period out period print Ln and what this does is pretty much print a line
on your computer now in your parameters go ahead and write whatever you want hello YouTube
now go ahead and save this and you can go ahead and find a HelloWorld program from somewhere
on the internet again I just uh talk to you guys through that real quick I promise uh
uh I’m not it this isn’t even part of the tutorial the tutorial is just to show you
how to run this so I’ll be teaching you about all this means later so go ahead and this
is where the tutorial really begins go ahead in the command prompt and the first thing
we need to do before we run this program is actually compile it now when we compile a
program it pretty much takes what we written and changes it into something called a class
file now your computer can’t read any files called Java it can only read dot class so
that’s a compiler job to take that dot Java and change into something dot class that your
computer can understand so right now what we need to do is find this file and go find
it you use something called CD backslash and what this does is take you to the very beginning
of your hard drive and this is just a quick tutorial if you never use command prompt for
once you’re in your C Drive press dir and press Enter this is gonna give you a list
that’s everything in your C Drive as you can see one my directories or folders is called
test so let’s go ahead and press CD which means change directory to test now we are
in the test so again from your C Drive press CD test now press dir and see what’s in this
and let’s see YouTube Java so how do we compile this YouTube Java well once you’re in your
test go ahead and press Java C which means Java compiler and then press YouTube dot Java
and this means I use the compiler on YouTube Java and then go ahead and press enter and
what your computer does is now if you press dir we now have a apples dot class so what
it does is take that Java file and change it into a class file depending on whatever
your name your class remember I named mine apples so now that we have a class file a
file that the computer can understand we can actually run this program so let’s go ahead
and type Java and that means run this program and then type in the name of your class which
is apples and now when you press ENTER it says hello YouTube so that’s a quick tutorial
on how to run simple Java programs and again I can’t stress this enough don’t worry if
you didn’t get that HelloWorld program that’s not even the tutorial I wanted to teach you
guys today the tutorial was learn how to run these simple Java programs from the command
line and in the next tutorial I’m gonna be clearing a bunch of things up so just practice
running a simple program I suggest you just go ahead and copy a HelloWorld program from
the internet somewhere and once you do just practice running it and if you have any questions
you can just send me a message on youtube or leave a comment and I’ll try to get back
to you but thank you guys for watching hopefully now you know how to run a simple program even
though you don’t know what it means yet so again thank you guys for watching make sure
to subscribe to my channel and I’ll see you next tutorial what’s up everyone it’s Bucky
and welcome to your third java tutorial now in this story only showing you guys how to
download something called a IDE where we’re going to be writing our Java code so again
there’s one more last thing I need you guys download I promise and then we’re actually
going to be start program in Java so I’m in the less it’s order I showed you guys how
to create a program in any notepad or any text editor and how you can run it from your
command line but the only problem with this and it’s kind of a big problem whenever you
have program like this in a regular text editor and say you have like a thousand line program
whenever you try to compile it and run it if something is wrong with it you have no
idea what’s wrong and you don’t even know where to look therefore it’s sometimes useful
to get a better editor just for Java made specifically so that’s why we need to down
something download something called I de and I’m going to show you guys how to do that
right now go ahead and open up your internet browser and go ahead and click eclipse.org
in eclipse is pretty much a special text editor for only Java so once this loads go ahead
and on the main page you’re going to see something called downloads go ahead and click downloads
now this is going to give you a couple on downloads to click from what you want is either
the first one or the second one I got the first one just because it includes a little
more and go ahead and if you’re on Windows go ahead and click Windows and what this is
going to do is it’s going to download um an Eclipse IDE and that’s pretty much arm pretty
much the text editor for Java I’ll show you guys what it is in a little bit but where
it’s going to be is if you go to computer and then go to whatever wherever your downloads
are you’re going to have something called a zip folder what you need to do is extract
you’re going to have a folder like this right here we need to do is right-click it and press
extract all then once you click extract all it’s going give you a little wizard once you
extract all that information you’re going to get a regular folder like this this is
pretty much like a compressed stuff and get all the information that you need to extract
it that’s what you do with any zip folder by the way now once you have your regular
folder you can double click it and now your Eclipse program is in this and it’s the little
one that says application with a little Eclipse logo next to it and what I did is I right
clicked it and I created a shortcut or you can press send a desktop and this gives you
instead of having to go through your computer hard drive you have a nice little shortcut
on your computer right here where you can just click it and start writing Java programs
so again it’s just a basic download I just want to show you guys walk you through a little
bit but once you do all that you have the Eclipse program on your computer so double
click that and your Eclipse program starts running just select a default workspace anyone
is fine and what this program does is allow you to edit code so in another cool thing
about this it has a compiler built right into it so we can just run our code right from
the same program you don’t have to mess around in the command line so what we need to do
first is go ahead and press file new project or Java project doesn’t matter one go ahead
and press a Java project now you need a project name I’m going to name my Bucky and go ahead
and press next and then go ahead and press finish you probably could press finish but
now you have a project named Bucky and it just puts everything into a project so you
can if you’re working on like a different Java thing for a different company but for
here we’re only going to be working with one project so we only needed to do that once
next you have a project called Bucky on the left hand side of your screen and go ahead
and press this little arrow and it D collapses or expands this little pain and you’re going
to see something called a JRE system library and a source we want to work with the source
file so go ahead and right click this and press new class since we want to create if
you remember everything is in class in Java so go ahead and click this and you got a neighbor
class something go ahead and I’m going to name mine apples and go ahead and press finish
now as you can see it already starts writing the code for us public class now I’m not going
to be teaching you how to write code in this tutorial I already have a class named apples
from last tutorial so I’m just pretty much I just wanted to eat you guys set up an eclipse
in this tutorial so um let me go ahead and paste a program I already wrote it’s the same
program I wrote in the last tutorial and now once you have a program I’m just going to
show you guys how to run it and then next story I’m showing you how to write a thing
how to run programs in Eclipse what you do is press this little circle with a triangle
in it and that says run and if you go ahead and press that what your program does is just
go ahead and run as java application go ahead and click OK ok and down here it just runs
your program so that saves you a ton of time from saving it finding the path going in command
line this is about eight thousand times easier than using a command line so again follow
those instructions and I want to show you guys one more reason why this is useful in
the command line in notepad if we had an error then it would just mess up in a wouldn’t tell
us what’s wrong in this one say instead a system where you wrote cysts something like
that that isn’t a valid code so whenever we try to run this and press ok it says error
error exists and then down here it says all right where does it exist on line three right
here so you go one two three here’s where your error is BAM you know exactly where is
and what you need to fix so again eclipse is a really powerful tool and that’s the last
thing I wanted to teach you guys and now we are finally ready to learn the java language
so now that you have done all that make sure to check out my next tutorial or i’m going
to be teaching you all this crap finally means and finally how to write the Java of language
in syntax so again I want to thank you guys for watching I thank you guys for sticking
with me running all of these programs and getting java set up I know it’s pain in the
butt but thank you guys and again make sure to subscribe my channel thanks for watching
I’ll see you next tutorial what is going on everybody welcome to your fourth java tutorial
and in this story we’re going to be writing a basic hello world program but before we
get started let me point out to you guys one thing now I told you guys at the point of
downloading Eclipse was check for errors and whenever you get those error messages it’s
going to say what line that the error is on so we can fix it but the thing with eclipse
and it’s odd that it comes default like this by default it comes without showing the line
number so before you get started let me show you guys how to do one thing that I know a
bunch of you guys are going to send me messages ask me how to do in your window tab at the
top go ahead and click on preferences and then your preferences tab is going to pop
up go ahead and expand your general editors text editors and once you click that it’s
going to have something that says show line number go ahead and click show line number
and go ahead and click apply now if you guys could guess what this did it wouldn’t surprise
you show the line number right there now we have our line number so whenever we get errors
which we’re bound to get we’re going to know where to go and we’re fix them now as promised
let me get to the basic Java program in which you’ve all been waiting for now in Eclipse
once you create a class I already starts writing some of the code for you and it creates a
class now again I know I told you guys unless Stora but let me stress why a class is important
in Java everything begins with the class so if you don’t have a class then you don’t have
Java or excuse me Java I don’t know what the heck you have if you don’t have a class but
you need one in Java so again everything we’re going to be writing in this story is going
to be inside your class semicolons so make sure you’re not typing out here or anything
like that in I’m going to be telling you guys exactly what class is later but for right
now all you need to know is to type inside it so just bear with me here now inside your
class the first thing we’re going to make is something called a method now what method
is is basically a recipe on how you want to run your program now the first thing your
computer does when it runs a Java program is it looks for a method called main and if
it doesn’t find the method main it has no idea where to start so in your computer in
Java built-in is the instructions to your computer all right the first thing I want
you to do is look for main and start there and from there I’m going to tell you what
to do so since that’s case the first thing we need build is a method called main so let’s
go ahead and do that so before I even start with that I wanted to you guys what the basic
layout of a method is before we can even start building main now I told you guys method is
pretty much like a recipe so let’s go ahead and pretend we’re writing a method now say
we have a method called bake cake what this would be is the method header right here again
the method header is pretty much um a substitute for the method and name so bake cake is the
name of the method and this is also called the method header now inside your method or
inside your recipe if I will go and continue that analogy is all the steps that you need
to take bake that cake so for example one would be mixed batter and the next one would
be put in oven and you probably have some other stuff ever at eat the eff and cake sorry
for cussing but again this is called the method header in the instruction of how you want
to do things is called the method body and all this together the head in the body that’s
called the method who would have guessed it so now that we know pretty much how to name
a method and how to put statements inside a method and what they are let’s go ahead
and write a basic method and again I told you guys all about main before so let’s go
ahead and do it go ahead and write public static why is it political it up oh this is
oblique public static void main and then in your main put parentheses input string Arg
s and 10 put square brackets now again all you have to pay attention is this is your
main method right here all this stuff I’m going it’s important and I’m going to be telling
you what it means but I don’t have time in this tutorial to tell you what it means so
again this is um what I named it bake cake this is all this is and I know that you see
a bunch of different keywords and trust me just bear with me you don’t need to know them
right now so just copy as I do and as I say is that even saying I don’t know but just
follow on now that we have a name of our method we need to give it some instructions and all
we want this method do is print something out on the screen so let’s go ahead and write
system dot or period what I write period right there oh that’s kind of American system dot
out dot print line and after this you want to go ahead and add parentheses and write
hello youtube and i know i spelled YouTube wrong but who cares now right semicolon now
let me tell you guys what I just did print line is a built-in method and what this is
going to do is print a line out on your computer now if you’re saying that you’re probably
asking all right how come I needed to write system out then if this knows how to print
a line well print line can actually is pretty versatile method it can actually print line
to a database or print line to your network or print line to other things but right now
we want to just print it to our system so again I’m pretty much just telling you how
to work with eclipse right now so just bear with me right here now once we have our method
built we want to go ahead and run this so go ahead and click this little button on the
right hand side of your screen and it’s going to run the program go ahead and you get this
click OK and at the bottom right here you get something called hello you I too and again
that’s what oppressed so that is how you build a basic method using of course your class
what you need your method header in your method body and again your method header in your
method body together create something called a method who woulda guessed it so that’s your
first tutorial on how to create a hello YouTube or hello UI tube program and I know you you
guys don’t know what everything means right now but I don’t have time to go through every
one of these things every one of these things these keywords right here actually takes an
entire tutorial to describe so um just bear with me just stick with me for now and now
that you guys know how to create a basic program I can begin teaching you the more complex
stuff and yes Java is a entirely completely complex program so just follow along with
me for now type this out and once you got your program working you’re ready to go on
in the next tutorial so I want to thank you guys for watching this story make sure to
subscribe to my channel if you have any questions to send me a message but if not just move
on in my next tutorial so again thank you guys make sure to subscribe and I’ll see you
next time what’s up guys is Bucky welcome to your fifth java tutorial and in this story
I’m going to talking to you guys about something called a variable now what variable in Java
is is pretty much like a placeholder for something else now if you remember from math class back
in like seventh grade or whatever whenever you had a variable and it was usually named
something like X you could have it set to a value like 73 and then whenever you use
X in a program or a calculation or something X will take the value of 73 and that’s pretty
much the same exact thing a variable does in Java you assign something called a variable
name to value then whenever you use the variable people know that it’s not really the variable
but actually stands for that value so let’s go ahead and make one of these in Java now
to make one of these in Java the first thing that you need to do is tell Java what kind
of variable you’re going to be working with and there’s a bunch of different kinds of
variables you can work with in Java you can use integers like 3 you can use integers with
decimal points like 3.14 you can use letters like s you can use strings of characters like
Bucky and so once you have that decided you need to have a way to tell Java what kind
of variable you’re working with so it doesn’t get confused so we’re we’re going to be working
with today is something called a double now what a double is is it’s a little bit above
it’s a keyword that tells Java all right you’re going to be working with a number but this
number can have a decimal point as well so um after you tell Java what kind of variable
you want to work with you got to give it a name so let’s go ahead and say we’re going
to be working with a variable called double and we’re going to name it tuna now after
you have a variable called tuna you need to give a value so go ahead and write 2 none
which is a variable name and then go ahead and press equals now what equals is here is
something called the assignment operator and what it does is assign a value to tuna so
what that we are we’re going to assign it let’s go ahead and write five point 28 my
favorite number five point 28 so here’s what we did so far we told Java that we’re going
to be working with a variable called tuna and then it’s going to be a double meaning
that has um numbers on both the left and right hand side of the decimal point again an integer
is only a whole number like eight ten negative four and a double has a fraction like five
point two eight eight point one eight so again we told that tuna is double it has a fraction
next we said all right what’s the value of tuna well here’s the name here’s the assignment
operator and here’s the value tuna equals five point two eight now we have a variable
that has the value of five point two eight that we can throw into any Java program so
let’s go ahead and do that and how we do that is just like we did before just print it out
on a screen so let’s go ahead and erase system on the type of write system dot out dot print
and in your parameters instead of typing a string of text like this is a strength all
we have to do is type the word or the name of the variable such as tuna and that would
print tuna out on the screen don’t believe me let me show you guys let’s go ahead and
run this and as you can see down in our little run box it has the variable five point two
eight so that is how you write variables out on the screen using Java in another cool thing
that you can do with these variables is unless order I’ll show you guys how to write strings
of text on the screen you can also combine these variables with strings of text so let’s
say we want to write a system got out print line and get out of here Hoss and in our print
line we’re going to say I want then go ahead and press space actually this brings me to
another point which I will say right now there’s two different things system out and print
and system out and print line so let me show you guys what those do right now system dot
out dot print line and let’s go ahead so what’s this thing right now I want five point two
eight what do you want five point two eight movies I want five point two eight movies
makes no sense but just deal with it now let me show you guys what this does and I’ll show
you guys why it does it let’s go ahead and run this and it says okay we printed three
things but only is on one line I want five point two eight movies and let me show you
guys why this is there’s two different print statements that you guys learn so far a system
out print what you see in the first two lines and a system out print line what you see in
the next line well a print statement does a basic print with no line is it says are
a Java we want to print this but we want to stay on the same line and it says all right
so just stay on the same line stay on the same line and then after this move to the
next line so after you have print line what it would do is move the cursor to the next
line so if you printed anything after this it would show up on the next line don’t believe
me let me show you guys system.out.print and it can even have a basic print stay memory
here and let’s have apples let me go ahead and run this and as you can see this one moves
to the new line so that’s the difference between the print statement in the print line statement
any time you use a print statement it stays on the same line that you’re printing on such
as here so this whole thing’s on the entire line as soon as you have a print line statement
one does is when it gets the end of printing it it moves to a new line so that’s the difference
between a print statement and a print line statement and again that’s your quick tutorial
on how to use variables again this is called declaring a variable this is called assigning
a variable value again this is the name of the variable and this is the value this is
the assignment operator right here and anytime you want to use a variable to print out on
your screen just write system.out.print and then write the name of the variable right
there and it’ll print out on your screen so again that’s a quick tutorial on variables
and how to use variables in Java so thank you guys for watching make sure to subscribe
to my channel I don’t forget to check out my next tutorial and again thank you and I’ll
see you next time what’s up guys welcome to your sixth java tutorial and in this tutorial
I’m gonna be showing you a real quick way to get input from a user so one way that we
can get input from a user is to use something that’s already built into Java and this is
called a scanner and what the scanner does is take information that the user types in
from their keyboard and stores it in a variable so let’s go ahead and get the scanner first
and how we get it or tell Java where we need to use it is we need to import it so go ahead
and write import on your first line Java jav au TI l dot scanner and this is how you’re
going to be inputting excuse-me importing stuff from now on so I’m just get used to
that syntax if you don’t know exactly what this means it’s pretty much just getting the
scanner and telling Java we’re going to need it so of course in our class we need that
public method again so in our class body go ahead and type public static void main and
in your arguments type string Arg s with a square brackets what’s good good enough now
in your body of your main we need to actually get programming so we need to make a variable
that’s going to hold the input from the keyboard before you use it so to do this we need to
go ahead and write something out scanner SCA and NER this means that we’re going to use
the scanner next you need to give your variable a name and I’m going to name mine Bucky and
then you need to set it equal to whatever they enter from the keyboard so to do this
you need follow-on new scanner and in your parentheses right here a man my semicolon
first you need to type system dot in so here’s what’s going in right here or excuse me going
on we told Java we need to use the scanner which is a way to get information from the
keyboard we have a variable it’s a scanning variable called Bucky and the Bucky variable
is equal to whatever and formation that’s in the keyboard and system n stands for system
input and the only input we have in the computer right here is the keyboard so this pretty
much is short for whatever we type in for the keyboard hold it in our Bucky variable
and we’re going to tell you what to do with it right now so now we have input whatever
that’s going to be from the keyboard and it’s going to be stored in our Bucky variable what
we want to do now is just print it out on the screen so you remember from the last tutorial
how to do that system.out.print line and in your parenthesis you need to type pay attention
the first thing you need to type is the name of your variable and that’s going to be on
whatever you made up here again this Bucky you don’t have to write Bucky of course you
can write anything you want now press Bucky period next line and what this is going to
do is allow you to pause and wait until you get input from here so again let me run this
program and I’ll show you guys what it does go ahead and press ok and now down here is
going to say a now press ENTER and it’s going to output hey now so remember it had a blank
cursor said hey now once you press Enter it just repeated it again and I’ll show you guys
what happened right there again one last time we imported this scanner if we didn’t import
it we can never use it since Java doesn’t really like to just gather everything it only
uses the things it needs it’s very um I don’t know Noba like it’s only takes what its needs
very courageous a programmable age but anyways what we did in our main function these are
the only two lines you really need to look for we made a variable called Bucky and it’s
a scanner variable we said we’re making a new scanner variable that’s going to be equal
to whatever the user inputted in this example hey now now hey now equals Bucky or Bucky
equals hey now so what do you want so anytime you print out Bucky is going to print out
hey now so instead of system.out.print line with text in here we actually change that
text for Bucky next line and again what that did is pretty much take that hey now variable
and put it in here and that’s why it printed out hey now so that’s your quick tutorial
on how to use the scanner to set it equal to variable and then use that variable to
output on your screen using the print line method so that’s your basics on how to gather
input from the keyboard and we’re going to need this input to use in functions later
on say we want to make a mortgage calculator or just a shopping cart that’s how we do that
so again I practice this just copy the source code as I do remember you don’t need a name
a name your function Bucky so go ahead and practice this and thank you guys for watching
hopefully check out my next tutorial don’t forget to subscribe to my channel and thank
you and I’ll see you next time what’s up guys welcome to your seventh java tutorial and
in this story I’ll be showing you guys how to make a basic calculator using variables
and other things that we already learned so far so in your last order I showed you guys
how to get input from a user using something called a scanner and we’re going to need that
again and I already imported it so the first thing that we’re going to want to do is go
ahead and make a scanner variable so let’s go ahead and write scanner and I’m going to
name mine Bucky again and again I’m going to set it equal to new scanner and also I
want to put system in so it knows where to get input from so or a system dot n and that’s
all you need to do for now the next thing we’re going to need is three variables we
need one variable to hold the first number one variable to hold the second number and
our less variable is going to hold the answer so you can they’re going to be doubles by
the way so you can go ahead and declare them by writing double F num for first num go to
the next line alright double s known for second num or here’s the neat little trick if you
have many variables of the same type and by type I mean double or int or something like
that since you have many double variables you can write them all on the same line it’s
a nice little shortcut so write s num and answer you can name your variable as anything
you want I just usually have shorter variables since I don’t feel like type and Hall up so
the first thing we want to do on a character on our excuse me calculator is just print
a line of text that says enter first number so the user knows what to do so go ahead and
you know how to write this system dot out dot print line print line and your parameters
just go ahead and write enter first num and then put a little a semicolon right there
if you want and now we can go once we have that all this is going to do is put a line
of text enter first num on the screen now what we want to do is have a way to enter
a number and have it stored and F num so go ahead and press F num equals Bucky remember
this is our scanner variable and right next double and that brings me to another point
now in our last tutorial I showed you guys something called next line and it was right
here and that was for Strings each data type in Java you need to give it its own method
since you need to tell what you’re going to be inputting in there so it knows how to save
it for example if this was strings you’re going to input in there like Hello you’re
going to put next line but since we’re inputting a number you’re going to want next double
because double is the type of number so now once we enter this number and it can have
decimal points it’s going to be stored in the variable F numb and we’re going to need
that later so now we have to do this exact same thing for the second number so let’s
go ahead and copy this line since I’m too lazy to type it where’s the copy they are
at us and next we want to print enter second number and now we just need to do the same
thing go ahead and copy this and after that prompt pops up you’re gonna there we go you’re
going to want to store this variable in s num so the first number you’re going to type
is in be stored in the variable F num and the second number you type is going to be
stored in the variable s num this stands for first number and second number now what we
want to do to get that answer that we have those variables is just add them together
so go ahead and write answer equals and you’re going to want to write F num plus s num and
now we have whatever number that F num and s num is going to be stored and answer now
it’s stored in there but we need a way to output it to the screen to see what it was
so let’s go ahead and write system dot out the print line and in your parameters just
write answer this is going to do is output answer whatever it was to the screen so go
ahead and run this program and hopefully I didn’t get any errors and here’s our program
right here enter first number let’s do 30 4.6 move my cursor out of the way press enter
enter second number um fifty four point two press Enter it’s going to give us our answer
eighty eight point eight zero zero zero one and this is actually something that I want
to talk to you guys about and I’ll be talking to you guys about it in the next tutorial
well probably not in the next one but um this brings me to a good point which we don’t have
time to talk about in this tutorial but I will get to shortly so basically what I did
and our first number entered it and our second number enter it and then gave us an answer
pretty much and again to walk you through this one last time what I did is import the
scanner so I could use the java scanner and then i wrote everything in my main function
because that’s where the computer looks first the first thing i did was write a variable
for a scanner just so we could use it next i made three variables that were double which
means numbers first number second number answer the first thing i did was have a little prompt
that should set a enter first number just so I knew what was going on for the user next
I use that little scanner variable and nextdouble method to have whatever I typed in the keyboard
to be stored in the first number then I just had something says enter second number and
then I had it have the user input something else and wherever they input at that time
is stored and s num and then I just outputted um whatever those two were added together
the sum of that and I just printed it out online screen so that’s a very basic calculator
and it had one flaw in it and that was giving us many decimal points and I’ll show you why
that is in I don’t know what tutorial but it’s going to be coming up pretty soon whenever
I deal with numbers but again that’s a basic calculator that’s how you build it using a
new method called nextdouble that we learn and also how to combine everything we learned
so far and build a function a functioning program so again practice this get good with
it make sure you understand everything we did up to this point and once you do you’re
ready to move on to my next tutorial so thank you guys for watching hopefully I see you
next time and don’t forget to subscribe to my channel so thank you and I’ll see you then
sup everyone its Bucky welcome to your eighth java tutorial in this tutorial I’m going to
be talking about a new type of data and that’s called an int and what it is is pretty much
not like double before where you had numbers like three point five four or you could use
fractions or decimal points with int it stands for integer and integers are whole numbers
like 6 or 75 or 76 and you can only use whole numbers without a fraction and no decimal
point so another thing at one point now is whenever you use int like to defy divide and
multiply and add and subtract whenever you use two intz to do these operations your answer
is also an int so even if your number comes uneven like 11/4 that doesn’t divide evenly
but when you try to do it on your computer with an int you get an int as a result so
let me show you guys with edit let’s go ahead and make three variables girls boys and people
and let’s go ahead and set these to some values let’s go ahead and we’ll start out with showing
you all of the math operators girls equals six boys equals three and people equals girls
plus boys now I showed you guys how to use this math operator and the last one the plus
sign to get a simple sum so now we can go ahead and the sum of girls plus boys is now
stored in people so I’ve put system dot out print line and in our parameter go ahead and
put what is it people and now if we go ahead and run this we get nine since six plus nine
excuse me 6 plus 3 is 9 and so that is how you can use addition with Java but addition
isn’t the only thing you can use you can use minus or subtraction to get the difference
which 6 minus 3 is 3 you can also do some other cool ones in the symbol for multiply
is actually the asterisk which is that little symbol above the eight so whenever you want
to multiply make sure to use that as you can see six times three is eighteen divided is
a special one now whenever you do this you’re going to get two but let me show you guys
something where if you divide it uneven say you wanted to divide eleven by three let’s
go ahead and see what our result is three well we all know that 11 divided by three
doesn’t equal three what it equals is three point something nine divided by three actually
equals three so what exactly is going on here well Java said all right you want to work
with intz well it’s our whole number so whenever you ask the question in intz i’m going to
give you an int so if you want to get um this number exact you need to use double so go
ahead and press ok and there’s your answer three point six six so that’s difference between
in and double it gives you whole numbers and double gives you um like a fraction of a number
or numbers with the decimal points so anyways there’s one more thing that I can help you
out with when using instead of I’d and that’s something called the modulus now we all know
that 3 goes into 11 3 times in that will give me 9 but you have two things left over whenever
you do that and that’s where the modulus comes in the modulus pretty means alright when you
divide by a number by a number you get a whole number aka an int but you also have some left
over so let’s go ahead and run this and see what we get it says 2 in the modulus if you
remember from math class this is another way of finding the remainder so again when you
divide by 11 by 3 you get 9 I mean excuse me you get 3 which 3 times 3 is 9 but you
have 2 left over so that’s where that 2 comes from whatever’s left over is the modulus so
that’s how you can use the modulus along with int to find the exact value so again let me
give you guys one more example this one might be easier if you have 7/3 you’re going to
get the answer to but you’re going to have one left over so if you divided by two such
is this you’re going to get the answer to but if you have the modulus you’re going to
get to answer one since you have one left over right there and that believe it or not
is going to be useful in a bunch of things that you won’t even expect like when we’re
finding random numbers and stuff that I’m going to be teaching you later but for now
I just wanted to show you guys what the int variable type was and also how to use different
math operators so uh thank you guys for watching practice this little um I don’t know what
this program is girls and boys and people counters I guess and once you get good at
all the math operators you’re ready to move on to my next tutorial so again thank you
guys for watching make sure to subscribe and I’ll see you next time what’s up guys welcome
to your ninth – Java tutorial and this is where I’m going talking to you guys about
something called assignment in increment operators now these are neat little tricks to have when
you’re working with a Java they’re going to save you a bunch of time and help you out
with numbers a little bit so let’s go ahead and make two variables I make one call tuna
and set that equal to five – whoa and make another one called bass in case we need it
I don’t know if we are beset equal to 18 now what the increment variable does is allows
you to add one very quickly to the variable and you can do this by pressing plus plus
and then the name of variable so right now by pressing plus plus tuna we change tuna
which was five to six now let me show you guys just so we can I have something you have
to take my word for it print line and go ahead and put a tune in there and go ahead and run
this baby and as you can see what was five now equals six so that’s how you can use plus
plus to quickly change variables value by adding one now another thing that you can
do is instead of putting it on and separate you can throw this right into the system print
line method and as you can see you still get six now this is called pre incrementing and
what this does is it changes the value of the variable before it uses it but I want
to show you guys something else whenever you use post incrementing what this is going to
do is it’s going to use this variable as five and then it’s going to change it to six so
let me go ahead and press ok and as you can see once we do this it gets five and not six
so what this did is it changed variable but it didn’t do it until after it already used
it so if we were to print it out again it would get six so let’s go ahead and do that
save me some time by copying this baby or get pasted there so now that here’s what’s
going to happen this is going to change the variable six but it’s not going to do it until
it after it already outputs it is five and now once at six is going to show six right
here so may show that as you can see five and then it changed it to six and then we
just outputted the regular variable and this doesn’t only work with a addition you can
also use this with subtraction by pressing – – you can change it by subtracting one and
getting four and let’s see what else there is what else is there um you can also do something
else and this is called an assignment operator so now we can know how to use the increment
operator using two plus signs and also using two minus signs to subtract one you can also
use the assignment operator let me get some space right here to do it if you want to do
more than one and instead of changing value of tuna and say you wanted to add five to
tuna sit you a platoon ax equals tuna plus five and what this would do is take that number
five add 5 to it and give you the value of 10 which I will show you right here 10 now
this is a pretty simple way it takes the new variable and sets it equal to the value of
the old variable plus the new number but there’s the easier way you can do this what you can
do in sub tune equals 2 plus 5 you can do tuna plus equals let’s get a new number 8
and what this does is take the new variable you want to use tuna and just a date to it
so it’s a lot easier way than typing all that so now we should get the number 13 and we
do just like that so that’s called um I think it’s called assignment operator but I’m not
exactly sure it’s how you can use + equals to add this number to the old variable to
get brand new very and also just like anything else you can use this with subtraction to
subtract a from even with multiplication to multiply 8 and if you do this you should get
the number 40 and you do so that’s how you can use basic increment operators to increment
one very quickly using plus plus and minus minus for subtraction and also assignment
operators so you can assign a value to a new variable very quickly without having a press
tuna equals tuna times a or something like that so those are just some nice little shortcuts
that you can use so get familiar with them because if you do it’s going to save you a
bunch of time and if you don’t then you’re going to waste a bunch of time so thank you
guys for watching my Java tutorial make sure to subscribe to my channel and again thank
you for watching now see you next time sup guys welcome to your tenth job tutorial
in this tutorial I’m going to be getting to the actual good stuff in Java so in this tutorial
we’ll be showing you guys what if statement is and how to use it to make a decision there’s
going to be a lot going on the story so pay attention it’s going to be sweet what if statement
is is pretty much how your computer makes decisions you’re going to give it a test such
as am i a boy or my girl and your computer looks at this and if it says your boy it does
one block of code but if it says you’re a girl it does another block of code for example
you could build a program if you’re a boy take you to a boy website but if you’re a
girl take you to a girl website or something like that so what we need to do here is build
a if statement and to do that go ahead and write if now after that you have something
in parentheses now what in is in your parentheses is called the condition but what the condition
actually means condition is just like the technical term what it is is actually a test
whatever you want to test you’re going to have two choices for now say we have a variable
called um let’s just name it test and let’s make it int int test is equal to 6 so now
we have a variable that we can test so let’s go ahead and test this and let’s go ahead
and say if test is equal to 9 and this brings me to another point you’re testing operators
there um let’s see probably six different ways I’ve taught my head that you can test
the first thing you can do is to see if something is exactly equal to something else so this
means if six is exactly equal to nine remember you don’t use one equal sign because when
you use one equal sign that means you’re assigning it to value when you’re testing it you use
two because you don’t want test the equal nine you just want to test of eight is equal
to not so that test if the variable called test is equal to the value nine if you want
to test if it’s not equal you need explanation point equal sign and this means not equal
and of course as expected you got your less than signs is six less than nine is six greater
than nine is 6 less than or equal to nine or a sixth-grader or equal to nine and those
are all self-explanatory I’m not going to show you guys exactly what those means but
for now I’m going to use the most basic one and what we’re going to be testing right now
is if the variable called test is exactly equal to nine which it isn’t now I told you
guys that you have a test and this test can either go it is or isn’t and that’s where
your computer makes a decision if it is then after your if statement you have something
called a statement your first statement and this is also called the body now your first
one is you need to tell your computer what it’s going to do if the test is true if test
is equal to nine then we want you to system.out.print line that’s right yes just write something
simple now the first thing you do is tell your computer what to do if test is equal
to nine and this what it does if it is equal to nine but as you can see test isn’t equal
to nine so what do we want to do now well if that isn’t true then we give you one more
option and that’s the else and let’s just go ahead and copy this copy and paste where
are you and let’s go ahead and write this is else so let me run this free eyes and I’ll
show you guys what happens press ok and our final result is this is else so let me show
you guys clear things up how if-statement works how if a statement works is you write
if and then you have a variable so it pretty much is exact same thing as saying all right
if test is equal to 9 I want you to print yes but if it’s not equal to 9 I want you
to print this is else so we’re going to have the test one thing if the test is positive
have this else if the test is negative have this but say we had something else like if
test was less than 9 which is true well since this test is true is going to do the first
option and not the second option again it can’t do both of them it can only do one or
the other so let’s go ahead and run this and it’s going to say this time yes so that is
how you can use different testing operators such as equals equals less than greater than
less than equal to and that’s how you use a simple if statement to give your computer
two choices again it’s just like saying if this test is true do this first thing else
do the second thing and don’t forget to use your curly braces to do the body of the first
thing and then you’re out statement and then your curly braces to do the body of your second
choice and I’ll be chaotic excuse me I’ll be clearing this up for you and next couple
tutorials but I hope this is pretty self explanatory just play around with it for now it’s the
best thing to do to learn so just copy this throw in some new variables and soon enough
you’ll get the hang of it so thank you guys for watching that’s the basic if statement
how to tell your computer to make a simple decision so again thank you guys for watching
make sure subscribe my channel and don’t forget to check out my next Java tutorial so I’ll
see you then sup guys welcome to your 11th java tutorial and this story i’ma teach you
guys how to use multiple tests in the Java program now in the last tutorial I showed
you guys how to test the one thing such as if um let’s say apples was less than 3 then
do something well there’s actually a way to in your if condition test many tests in the
same condition so let me go ahead and demonstrate there to do demonstrate this point let’s go
ahead and make a simple dating website so we need two variables and boy and Inc girl
and let’s go ahead boy set them to 18 nice young book as myself and drill setter equaled
a 68 shipped me an old cougar so let’s go ahead and make a simple um if statement and
in the test condition as I told you guys before we learned how to test one thing so if boy
is greater than 10 we would execute a certain block of code so let’s go ahead and do that
system.out.print line and if he’s older than 10 wilbur i you can enter since we can grant
information else if he’s less than 10 then what do we want to do um let’s just copy this
save us some time copy and paste there we go um you are too young so let’s go ahead
and run this real quick make sure everything is working and since boy is greater than 10
it says you can enter so that’s what I taught you guys last time how to do one test in an
if statement but there’s a way where you can do multiple tests in the same condition now
say you wanted to make sure that the boy is greater than 10 and the girl is less than
um 60 since we don’t want any senior citizens on our site no offense but this this is a
site for younger people only so what we would do is use something called the double ampersand
in this stands for and and whenever you use this that means that either test on either
side of this has to be true for this to be true so for example if boy is greater than
10 and girl is less than 60 which is false you want to print you can enter else print
you are young and again here’s what and means whenever you have this little double ampersand
and that’s a little symbol above the 7 on your keyboard this test has to be true and
this test has to be true for this piece of code to execute if either one of these are
false or if they’re both false then this code is never going to execute so let’s go ahead
and change this to you can not enter so if the boy is greater than 10 which is true and
the girl is less than 60 which is false 68 print this you can enter so it’s not going
to print that it’s going to print this you cannot enter so let’s go ahead and run this
and as you can see you cannot enter so let’s go ahead and what if we changes to the girl
was within the age limits 40 and we ran that baby again it would now say you can enter
so that is how you use something called multiple test in the and sign to make sure that two
tests are true so you can execute a certain block of code but there’s also another neat
thing besides the and and that’s called the or and to do that you use two little pipe
signs and that’s the key above your Enter when you press shift it’s a I think it’s called
a pipes like a pipe or pipe line or something but here’s what this means to little pipes
this means or in what or means is either this has to be true or this has to be true only
one of these have to be true to execute this first statement if they’re both false then
it’s going to just skip that and go to this so let’s go ahead and in another point in
an or statement this one has to be true or this one has to be true or they both can be
true such as right now so let’s go ahead and change this to girl equals 99 so only this
one is true but this one is false using the or thing you can enter such show up should
show up so let’s go ahead and we ran it and it said you can enter and let me show you
guys what happens if both of them are true um it should do the same thing girl he goes
forty-four run it again it says you can enter but again the only way that this is not going
to work is if both of them are false so let’s say if the boy was eight and the girl was
99 it would say you cannot enter so again to recap one last time if you want to do multiple
tests in Java there’s two things you can use in and sign and what this does is make sure
both the tests on either side are true and if it’s not true it does the else and you
can also use the or sign and unlike the and where both of them has to be true the or sign
make sure only one of them has to be true but if both of them are true then oh well
it still works so that is how you can use a multiple test in your java program using
the double ampersand in double double pipes to test either an and or so if you have any
questions or if this is confusing at all then I you can just send me a message and hopefully
I can clear things up for you but I try to make it real self-explanatory for area so
that’s all for this tutorial I hope you learned how to do multiple tests and make a simple
dating program so thank you guys for watching and don’t forget to subscribe to my channel
and I will see you next tutorial some guys is bulky welcome to twelfth Java tutorial
and in this thoron we teach you guys about something called a switch statement now what
a switch statement does is test one variable and depending on the out depending on the
value of that variable pretty much that gives you multiple choices so before we learn the
switch statement let me show you what we had to do with our knowledge so far say we let’s
make like a program that tells you what kids do at a certain age so say we have a program
that has variable called age and the kids age is three right now what we would have
to do right now is make it if statement for each age and put if age is equal to one and
then we would have to put something like um system then we would put out and stuff like
that and it will just get pain in the butt and then we would have after one would put
if age is equal to two is equal to two and then do your stuff down here as you can see
we don’t want to type all that stuff for each number so I wish there was the easier way
just to test age for a bunch of different things well actually you don’t have to write
ten different if statements if you want to test age ten times you can only write something
called a switch statement once and it will give you many different options so instead
of writing ten different if statements to see what a kid does from ages one to ten let
me show you guys what to do what you do is write the word is switch and what switch does
is find the variable value in the parameters so what variable do we want to test we want
to test age so after this you just go ahead and write curly braces and give yourself a
nice little switch body now instead of writing on a bunch of if statements all you would
have to do is right there called cases now what case means is if the value of age is
equal to one what do we want to do and after case one go ahead and put a regular : and
I don’t know if you guys can see this but this is a regular : after the one and not
a semicolon so in the case of one um let’s go ahead and system.out.print line so what
can they do it one arm you can curl and then after this you want to add something called
break now what break does is it means alright if this is true in age equals one then we
have no reason to go to the rest of the program so you can just exit and I’ll be talking about
that more later but for now just make sure you have it so you can just repeat this for
as many options as you want so in the case of two what do we want to happen let’s just
copy this copy save yourself some time um you can talk so in the case of two if H equals
two what do you want to do you want to print you can talk and then break and let’s go ahead
and make one more in the case of three again using lazy you don’t feel like typing it all
in the carry case of three you can uh get in trouble and I know I spell trouble wrong
but just deal with it so here’s what you do you put switch and then put the variable you
want to test the value of then you put the values that are possible after the word case
now after in the case body what you do is write re if H is equal to one here’s what
I want you to do if H is equal to two here’s what I want you to do if H is equal to three
here’s what I want you to do and the last thing you have in every switch statement is
something called a default and to do that you just write default and what this does
is if none of those values are true it does a default statement so let me scroll up a
little bit so you can see and again you don’t need a value for this like default for because
it already knows all right if everything else is false this is where your and do so that’s
why you don’t need a value so let’s go ahead and all right actually I’m gonna go ahead
and copy this since I’m lazy copy if default let’s go ahead and write um I don’t know how
old your I don’t know how old you are and of course we have a break at the end of this
as well if I can get it right break so let’s go ahead and run this with age equal to three
and let me show you guys what it does it outputs you can get in tolerable and it’s supposed
to be trouble but I typed it wrong so and let me recap well let me show you guys what
default does so if age isn’t equal to one two or three say Asia is equal to seven and
I run this it says I don’t know how old you are so let me recap one last time what this
switch statement does a switch statement takes the variable whatever is in its condition
and test it so then it looks through the cases to see what value that variable is equal to
if it’s equal to the value one it prints this if not it doesn’t do it at all then it looks
if it’s equal to the value 2 if it is it prints this if not then it skips this as well then
it looks if it’s equal to the variable 3 if it is it prints this if not again it skips
all of these and then if it doesn’t hit any one of these then it goes default and what
default means is I ran through all these options and none of them worked so by default I got
to do something this can’t be just a waste of a program so by default I want you I want
to output I don’t know how old you are so that is how you can use the switch statement
to test a single variable for many different values and this will save you a bunch of time
and keep you from writing a bunch of different if statements and it trust me it’s a whole
lot easier than writing a bunch of if statements so that’s your basic on the switch statement
um it will save you a bunch of time so thank you guys for watching and hopefully you learn
a little something copy this play around with it and pretty soon you’ll be expert it’s a
switch statement so again thank you guys for watching and don’t forget to subscribe to
my channel and I’ll see you next tutorial sup guys welcome to your 13th drop tutorial
and in this story I’m going to show you guys how to do something called a while loop now
what while loop does is it allows you to execute a certain block of code multiple times but
only write it one time so pretty much it saves you a bunch of time writing a code and let
me show you what the syntax is for this the first thing that we need is a variable and
I’m going to name my encounter and I’m going to set it equal to let’s go ahead and set
it equal to zero to begin with now the syntax for a while loop is just the word awhile and
this means begin your wild loop and what your while loop is going to do is whatever is in
the body of your while loop or curly braces it’s going to execute this code and let’s
go ahead and say system.out.print line and let’s go ahead and just print the variable
counter nothing special here so what this is going to do is it’s going to execute this
line of code multiple times so you’re saying alright how many times is it going to execute
well that is up to whatever you put in the condition so let’s write while counter is
less than 10 we want you to output counter so right now here’s what would happen it says
all right what’s counter zero print counter what’s counter zero print counter so this
loop will kind of go forever so we need a way to end the loop somehow so we need a way
to change counter so let’s go ahead and use the incrementing operator that we learned
less time and just put counter plus plus and let me run this real quick and show you guys
what it does run okay and in our little run box we get 0 1 2 3 4 5 6 7 8 9 just what we
wanted now let me show you guys one more time what this does we had a counter variable to
begin and it started it is 0 the first time we told Wow is all right while this counter
is less than 10 we want you just to write whatever number it is on the screen so the
first time it looped it was zero so outputted 0 and then it added one to it so then it was
one so now it looked at it again is counter less than ten yup let me put that on screen
now it’s two is counter less than ten yup and it did that again and again until it got
to ten and when it got to ten is 10 less than ten nope so I’m just going to not do anything
so that’s how you use loops to execute a block of code many times without having to write
it over and over again if we didn’t have this we would have to write um print our prints
they met 10 times and as you can see this saves you a bunch of time so again the syntax
for a while loop is wild and then put your test condition in um what are these called
parentheses and then put whatever you want to execute in curly braces right here and
whatever you execute is going to do that however many times you say so that’s your quick tutorial
on loops on the sawaal loop there are different kinds of loops where I’m going to be probably
going over in the next tutorial but this is your basic while loop so thank you guys for
watching I hope you test this out a little bit and play around with it and you’ll be
expert in no time so again thank you guys for watching don’t forget to subscribe to
my channel and I will see you next tutorial so guys is Bucky welcome to your 14th jump
tutorial and this story I’m going to teach you guys how to use multiple classes now so
far I’ve taught you guys how to build everything in one simple class such as this but usually
in a like 99% in time if you’re working for like a company or building a bigger application
or program any time you want to build something that’s bigger than something really simple
you need to know how to use more classes or multiple classes and then you can use those
all in your main class or let me just show you guys how this works so to get another
class hopefully you’re using Eclipse go ahead over to your source file right click it and
go to new class now go ahead and give this a name like tuna or something like that and
you’ll see why this is useful later on so now we have as you can see from our tabs we
move this over we have apples class and the tuna class now it started out writing our
tuna class for us it says public class tuna now anytime you see public it pretty much
means that this class is going to be available to the public or anything else can use it
so let’s go ahead and now that we have a class before I show you guys how to use it let me
show go ahead and write a little method in here now let’s go ahead and write a simple
method in this other new tuna class that we just built type public void and again public
means anyone can use it void means that it’s going to do something this method is going
to do something but it’s not going to return any data so then go a name ahead and name
your method I’m going to name my simple message since I’m just going to be printing out a
simple message and that message is going to be system.out.print line and let’s go ahead
and add something like this is another class so now we have another class and this is called
public class tuna and our method is public avoid and don’t forget to put a simple message
in here somewhere you can put anything you want and now if you see if we go ahead and
try to run this try to run it okay nothing happens right here and this is because I told
you guys anytime you run a Java program it looks for the first thing that says main and
runs it from there as you can see you don’t have main anywhere in here so it doesn’t really
know where to look first so in order to use this class we need to go ahead and use it
in main so here is our main function or method right here and it’s in the main class one
remember this is the main one that we use before it the other one is the new one that
we built so let me give you guys a little background whenever you use a method in another
class say we want to use this method simple message and it’s in the tuna class what we
need to do is go ahead and create an object of that class so the first thing we do is
put the class name which is tuna next we need an object name and you can name this anything
you want I’m going to name my tuna object and what this object is gonna allow you to
do is use all the stuff that’s in this class again if you didn’t create an object and you
had like five classes and what I know what class you’re talking about so that’s why we
need an object so we’re saying are a we have this object because we want to use something
from the tuna class and of course you need to set it equal to something and you always
said equal to new in the class name with empty parameters for now so now we have an object
called tuna object that we can use to get anything we want from this tuna class that
we just build so let’s go ahead and use it what you do to use this is go ahead and put
the object name which is tuna object spell it right tuna object and then after the object
name what you do is add a dot separator and after that dot separator you use the method
name so what was our method name uhm simple message so simple message empty parameters
and let me tell you guys why you use a dot separator in the method name because this
class even though we built one method right here it can have as many methods as one since
it can have a method name simple message simple message to dimple message um bacon and cheese
but it says all right we have this object we want to use in tuna class and we want to
use this method so if there are other methods we want to use this one so that is how you
use a specific method in a specific class by creating a class or excuse me an object
of that class so let’s go ahead and unlike before when we run this program we get the
message that we just built this is another class and so this is how you can use different
classes in your main program or your main method so this is a way that if you own like
a software company you can say alright Tommy we need you to build one class to do this
John we need to build another class to do this Stephanie we needed to build another
class to do this and then you is the head programmer would put all those classes together
and it’s just a way that different programmers can combined all of their work without having
to work on the same file so this makes it a lot easier again that’s how you use a different
class such as this an outside class and call it into your main method or function so that’s
your a quick tutorial on using multiple classes follow this tutorial exactly and play around
with it and soon enough there will be expert at it so again thank you guys for watching
make sure to subscribe to my channel and make sure to check out my next tutorial sup guys
is Bucky welcome to your 15th Jeff tutorial and in this tutorial I’m going to be teaching
you guys how to use methods with parameters now in this tutorial we’re also going to be
building a custom function where we’re going to let the user enter their name in the outside
class and it’s going to call it in the main class in just say like hello to whatever your
name is or something so if that sounds complicated then I’ll follow along and I promise I’ll
make it easier it’s probably easier just to see then maybe even say so follow-on so again
we have our main appleís class with our main function or method in here and we have our
outside toona class with the method that we call so let’s go ahead and clear everything
out of your public class tuna if you have anything in there because we’re going to be
adding a new method so go ahead and type as I do public void and we want our simple message
again and instead of just adding empty parameters this time we needed to take an argument in
our parameters and let’s go ahead and make a string variable and call it name so again
anytime you have something in your parameters is called an argument in an argument or extra
parameter data is pretty much any extra information that the method needs in order to work so
let me show you guys what this method actually does and you’ll see why it needs extra data
what it does is just system.out.print line it just prints on the screen hello and then
it prints the name so if you don’t have a name it will print hello and nothing so again
an argument is any extra information that the program needs to run so again what this
is going to do is print hello and then your name so before we use it we need to do a couple
stuff to our main function of course to enter our name we need to import the scanner or
else we have no way of importing a data to Java so go ahead and import java.util.scanner
and this is going to allow us to use a scanner so we can give information to our program
next we need to make a scanner object so let’s go ahead scanner name an input new scanner
and I believe that I tell you guys how to do this in the last tutorial so you should
know what I’m doing system in and that’s that for that line that makes that we can use the
scanner Mexico ahead and do what we did last time and create a tune object so we can use
this object to get the information from the tune class we just need that empty parameters
next let’s go ahead and print system.out.print line spell alright and we just want to write
a prompt to the user so it knows what to do enter your name here so this is pretty much
the only thing that’s going to go on right now we now have text on the screen that says
enter your name here now we need the next thing they enter to be stored in the variable
name so let’s go ahead and make string name so the variable name is equal to input next
line and I told you guys how to input integers using the scanners anytime you want to input
a string use this next line method so again anything that the user enters is going to
be stored in the variable name so now what it’s going to do is look at name and say hello
name so if you’re entered Bucky it’s going to say alright Bucky equals name so hello
Bucky so now before I do that we need to actually use that object to call the method so tuna
object and go ahead and put your dot separator simple message with your name parameters and
again unlike last time where you don’t use anything at all you have to put the argument
that it takes in here and this says again that this isn’t just a method that you don’t
need any X information for we’re going to give you this extra information for something
because we want you to do something with it so go ahead and let’s run this program and
then I’ll show you guys what does later enter your name here um bucky roberts and then it
says hello bucky roberts and let me talk you guys through this one last time we imported
the scanner because that’s how we uh how Java allows us to input stuff in the computer like
i typed in bucky roberts without this I wouldn’t be able to type in anything next in our main
function we set our a we want to put this this just allows you to use the scanner after
you imported it we next made an object because without object we can’t use anything in this
class as I taught you in the last tutorial next we just put a prompt on the screen we
learned this like in the first tutorial just showed what we need to do next we put all
right we have a variable called name we want this to be equal to anything we type in B
and that’s so if you have different users that are using this program doesn’t just type
the same message you can use it for a bunch of different users no matter what they type
in for their name next we set our write in the class tuna use a method called simple
message that takes an argument of name so it’s going to go look at all the classes find
the one called tuna and find the method that’s called simple message and and do whatever
it says to do and what this method says to do is say alright take a variable called name
which we already had we just gave it to it and then just print out hello whatever the
name is so it says alright hello Bucky Roberts so that is how you use a method with a parameter
and that’s what parameters do is just the extra bit of information that you might need
to run a program so again that’s your quick tutorial on how to use methods with parameters
in a different class so thank you guys for watching and don’t forget to subscribe to
my channel for all my latest videos and also check out my contests so again thank you and
hope to see you in my next tutorial what’s up guys is Bucky welcome to your 16th Java
tutorial and in this story I’m going to be teaching you guys how to use multiple methods
and also something called instance variables when working with classes so let’s go ahead
and open up our tuna class and clear anything out if you have anything in there and let’s
go ahead and the first thing I want to do is make a new variable called private string
and just put a girl name because we’re going to be making a program in the store l2 output
the name of our first girlfriend so the first thing you probably notice is instead of public
I put private and this is because when you’re working with classes right now we have two
types of variables public and private public variables any class can use that variable
but when you use a private variable only the methods inside this class can use it so the
methods that we’re about to build can manipulate and change and also access to this variable
if we were in another class like this one over here it couldn’t use this variable in
this class so private means private inside this class only the methods can use it inside
this class so let’s go ahead and make some methods the first method that I want to make
is public void set name and what this is going to do is set the name of whatever we put into
it into the variable girl name so of course we need a parameter string name so now we
have two variables name and girl name so let’s go ahead and add some instruction for this
method we’re going to put the girl name is equal to name that’s all that’s all we need
for this method and what this is going to do this whenever we use this method in our
main program whatever we put in for the argument for this method all it’s going to do is make
sure girl name is equal to name so it’s pretty much just putting girl name equal to whatever
you typed in next let’s go ahead and make a method to access that so let’s go ahead
and put public string and this is the return type let me show you guys in a second again
we know public means access anywhere the second thing after this is a return type and whatever
your method does it may or may not return something this method is going to return a
string so that’s why we need to put string and if your method returns nothing go ahead
and put void so now let’s go ahead and our method body let’s go put return girl name
that’s all all it does is a return girl name which was made up here next let’s go ahead
and make one last method totally avoid saying and this is going to be our final output to
the user so all we need to put here is system.out.print F and this is a new type of print if I didn’t
teach you before what it does is take something like your make sure I was felling everything
right your first girlfriend was percent s and whenever we use percent asset it needs
to know what string no I want to put in place of this well we have a perfectly fine string
right here in our get name so let’s go ahead and I won’t copy that I won’t be too lazy
get name so it’s going to say your first girlfriend was in whatever girl name is as defined up
here that’s what it’s going to output you’ll see what it does later but for now let’s go
over your apples one make sure you import your scanner and make a tune object so we
can access that class and now let’s go ahead and just put a basic prompt on the screen
so we can tell the user what to do system.out.print line and what are we going to print I just
put print something like enter a name of first girlfriend here just any prompt will do just
so we’re not lost so the user actually knows what to do and after that go ahead and we
need to make a temporary variable so we need to put string temp you can name yours whatever
you want I just name my template fun input and this is where we use our scanner variable
the next line with empty parameters and again whatever the user types in as their answer
it’s going to be stored in the variable temp so that’s what this line does this is just
a prompt this takes whatever they enter and stores it in the variable temp right there
next we need to do something with this so let’s go ahead and use our tuna object and
we need that to access set name and of course the parameters for this is going to be that
temporary variable temp so what it’s going to do is take the name that they entered and
set it equal to girl name right here it’s going to take it which is name set it equal
to girl name now we need to do one last thing now that we’ve got that name equal to girl
name all we need to do is do tune object– saying with empty parameters and what this
does is use the tuna object saying what is this you may ask the saying just outputs on
the screen arm your first girlfriend was and it’s going to be whatever they typed in for
the name so let’s go ahead and run this see if I got any errors and I don’t so let’s go
ahead and enter name of the first girlfriend mine was Kelsey go ahead and press Enter and
it says your first GF was Kelsey stands for girlfriend she was babe so let me tell you
guys what this does one last time import scanner we know what all this stuff does and your
name what this does is allow us to enter a name and it’s going to store it in that variable
called temp and what the next line does right here is say alright in your class tuna take
that variable temp and use it in the setname method so now it takes that variable name
temp which was Kelsey and stores it as girl name so now girl name equals Kelsey so it
says all right now what well next I want you to just use the saying method in the class
tuna so it says all right we know that girl name is equal to Kelsey now so now we can
use that saying what you told us to do right here and just your first girlfriend was Kelsey
and again if you don’t know what printf does then check out my C tutorials and I go over
this this is the common print function in the language C also you can use it in Java
but this is just another way to print so don’t let it confuse you so that is how you use
um instance variables and multiple methods so again you can use multiple methods in the
same class and don’t forget whenever you have a variable that’s outside a method again it’s
outside all these but it’s inside this entire class it’s called an instance variable so
that’s where I get that name from so I hope you enjoyed watching this tutorial I hope
you understand at least a little bit of it so thank you guys for watching make sure to
check out my next story I promise I’ll be clearing this up for you don’t forget to subscribe
to my channel and I will see you next tutorial so guys bulky welcome to your 17th java tutorial
and this story I’m going to show you guys about something called a constructor now what
a constructor does is it allows you to initialize variables as soon as you create an object
so for example whenever you created this variable right here as soon as you created your object
let’s go ahead and do that right now tuna let’s make them call tuna object like before
equals new tuna and of course we had empty brackets as soon as we did that and try to
use our object such as tuna object saying and what we do it if we ran this it said your
first girlfriend is null and this would be because whenever we try to use girl name it
didn’t have a value yet well what a constructor allows you to do is give this variable of
value as soon as you create your object so let me show you guys how to make a constructor
and then I’ll talk you guys through it one more time exactly what does now how you make
a constructor is pretty much exactly how you make a method the only difference is the methods
name has to be the exact same thing as the class name so let’s go ahead and write public
tuna and as you can see since we’re working in the class called tuna a constructor method
has to also be called tuna so let’s go ahead and what I want this to do is assign a value
to this string variable girl name so let’s go ahead and write string name of course and
I’m going to have this do the exact same thing is this set named it so girl name equals name
the only difference is instead of having to call the setname method we can just do it
all as soon as we create our object so let’s go ahead and now we have a constructor object
that we’re going to well let me just show you guys what it does so instead of before
whenever we use empty parameters right here we can use those parameters to pass an argument
such as Kelsey now let’s go ahead and run this and it says your first girlfriend was
Kelsey so that is a really a simple way of how you can use a constructor let me talk
you guys through this one more time and then I’ll show you guys another neat little trick
and if you want to initialize a variable before or excuse me as soon as you create your object
such as this all you have to do is create a method and name it the exact same thing
is your class and all you have to do is put whatever you want to initialize in here and
then whenever you create your object instead of leave them those parameter parameters empty
just put your argument in there and that will go to your constructor and initialize all
those variables for you so if you’re saying RA Y is building a constructor even remotely
useful why can’t I just leave those empty like before and use this little method right
here later on well say you had more than one object so say you had another object called
tuna object 2 and another thing I want to point out I don’t know if I told you guys
this before but every time you have an object it has its own set of variables so for example
say you have something in this one called Nicole I wasn’t named my second girlfriend
appropriately named to an object – and say you have a tuna object to this variable that
is what was it called girl name this is an entirely different variable than this these
two objects they can’t see each other’s variables so that’s the kind of beauty of creating object
that gets his own set of variables so now this object can have output saying and now
you can also have a saying for tuna object to not 21 saying and let’s see what this one
does right here it says your first girlfriend was Kelsey your first girlfriend was Nicole
so let me got give you guys will run down one last time the first thing you did is create
a constructor and again you did that by naming a method the exact same thing is a class what
this constructor allowed you to do is allowed you as soon as you created an object and we
created two of them right here it took that value and passed it in a girl name and from
there you can you just use a girl name anytime you want to use that object so it use girl
name which is Kelsey and tuna object and girl name which was Nicole and tuna object to and
pass the end of the method saying for both so again that’s not as important as how to
create an object or excuse me a constructor and again one last time what a constructor
does is it allows you to initial eyes variables as soon as an object is created so that’s
your real quick tutorial on how to use a constructor and what it does and will be coming across
that later on and it’ll be get easier and easier as I’ll show you guys how to use it
in a more useful application but for now I just want to show you guys the basics so thank
you guys for watching make sure to subscribe to my channel make sure to check out all my
contests and I guess I’ll see you next tutorial what’s up guys welcome to your 18th java tutorial
in this story I’m going to be going over some called nested-if statements and also else
if statements so I gave you guys a quick heads-up on whether if an else statement was in a couple
of tutorials ago but I’m going to give you a refresher or a quick in case for God and
then I’m going to be getting into some more stuff that we’re going to be needing later
so go ahead and make an integer you can have it whatever you want I’m going to name mine
age and set it equal to something like actually set equal to 60 next let me remind you guys
what if statement does what if statement does is it tests a condition and if that condition
is true so age is less than 50 it does a certain thing so let’s say if age was less than 50
which is not why I had to print out on the screen let’s make sure I got this type to
right for a go any farther um if it ages less than 50 then you’re pretty young so you are
young so it allows you to make a decision if a condition is true and we also went over
the else and what this does is a gives us a alternative unless that condition is false
so let’s copy that because we’re lazy and it’s put you are old let’s so go ahead and
see what this does right here it outputs on the screen you are old so what this did real
quick I’m not going to get an in detail because the told you later it looked at this variable
called age and tested if it was less than 50 if it was it was going to print this you
are young but it wasn’t so printing this and again this is how you can give java a way
of making many choices oryx or just one choice in this condition but what I wanted to talk
to you guys about in this story is not the simple if-else statement it’s something called
a nested if-else statement or a nested if statement and what it is is this instead of
just having one action if it’s true or one action if it’s false say if it was false you
wanted it to perform another decision well actually what you can do is take this entire
if-else statement and plug it in one of these things right here so say the age is 60 right
here if the age is less than 50 then it’s going to do this well the age wasn’t less
than 50 so it’s going to do whatever is in the else statement so let’s go ahead and make
another decision in it all right we already know that the age is greater than 50 so let’s
go ahead all right if in that case age is greater than 75 oh what do we want to do we’ll
just print out you are really old so if age is greater than 75 we want to print out you
are really old else in that case age must be greater than 50 but less than 75 what are
we going to print out we’ll pronounce something nice firm don’t worry you aren’t really that
old with much typos because that’s what they wanted so let’s go ahead and run this and
when we do it says you are old don’t worry you aren’t really that old and let me show
you guys what happened right here this entire thing is your main if-else this is what’s
going to happen if it’s less than 50 and this is what’s going to happen if it’s greater
than 50 now if it’s greater than 50 what did it which it is the first thing it’s going
to do is print out this statement you are old and then it’s going to say all right what
else do I do if it’s greater than 50 oh I got a whole other decision I got to make so
aside from this entire decision I got to make another decision is my age greater than 75
no at 60 well then I’ll go to this one don’t worry you aren’t really that old so again
that’s how you can embed an entire if-else statement inside another if-else statement
and you could have just as easily put this in the first one by I decided to put this
in else because that’s where our decision led so that’s your quick tutorial on how to
make if or excuse me what this is called is actually nesting when you have one if-else
statement inside another one it’s called nesting if statements or nesting if-else statements
so that’s your quick tutorial on how to do that in the next store I’m going to show you
guys how to use something called elsif so make sure to subscribe them looking forward
to it and I’ll see you then so classes pucky welcome to your 19th tutorial in Java and
in this story I’m gonna be going over something called an else–if statement you know what
else if statement is is pretty much a way of giving Java many options so in our last
tutorial I showed you guys how to build a if statement such as this one where we had
a condition which if age was greater than 60 then we want you to do something like system.out.print
line and copy that so I don’t have to keep typing it so if it’s over 60 say you are a
senior citizen let me type it right there we go so if statement allows you to do give
it one option we also have something called else which gives it another option say else
if it’s the less than 60 you are a young buck and whenever you run this make sure we don’t
got any errors it says you are a young buck so again a simple if statement what this allows
you to do is give it one option and an alternative option but there’s a way where you can do
more than just two options and you do this by in the middle of if and else you add something
called a else if and what this is is pretty much a third option so let’s say all right
if age is greater than 60 print this actually just put greater equal two else if age is
greater or equal to 50 want you to print you are in your 50s and we can have as many of
these else if statements as we want so unlike last time where we only had one alternative
it tests to see if age is equal or where it stands in many different tests so if it’s
greater than 60 do this and if it’s not greater than 60 then it must be less than 60 so else
if it’s less than greater than 50 do this and we can do this all the way down actually
let’s go ahead and just copy that save us some time copy and paste and it changes to
40 and 40 s so let me uh put 45 and I’ll show you guys why this does this go ahead and put
run and it says you are in your 40s so here’s what it did it can only do one of these things
so here’s what it does the first thing it does and remember our age is 45 that says
all right is age greater or equal to 60 nope it’s less so I’m not doing this is age greater
or equal to 50 nope it’s not so I’m not doing this is age greater or equal to 40 yes it
is greater than 40 so I am doing this you are in your 40s so that’s why it output it
you are in your 40s and again whenever you use the if statement as soon as it finds this
answer it exits the whole thing so it can only do this this this or this and since it
did this one since age was greater than 40 there was no need to go to the elf’s because
I already found its answer so that’s how you can give a variable many tests using it is
excuse me if else if else statement again the if is the main test and the else if statements
are alternative test if these previous tests are false so it’s pretty much is just a way
to give it a bunch of different options when testing the same variable or you can even
test different variables if you want to be dumb but um that’s your basic tutorial on
an elf’s if statement and how to use it in java programming again it’s called else–if
and it goes in between the if and else to give it more options so in the next couple
of tutorials I’ll probably be clearing this up later and showing you guys why it’s actually
useful in applications but for now we just wanted to show you guys the basics of it so
thank you guys for watching make sure to subscribe to my channel and don’t forget to check out
all my other videos so again thank you and I’ll see you next tutorial sup guys is spunky
welcome to your 20th Jeff tutorial and this story I’m gonna be talking to you guys about
something called a conditional operator now what conditional operators are is pretty much
another way of using an if-else statement but it’s really compact and it’s really small
so go ahead and create a variable called age and set it equal to 21 or set it equal to
what everyone it’s not going to matter what a conditional operator is is let me just show
you make a simple print statement system out print line and in this print line this um
operator is so small that we can write the entire thing as an argument and what it is
is this the first thing you need to do is give a test so if age is greater than 50 after
you give it a test you add a question mark and what this means is treat this as a boolean
expression so it’s gonna see if age is greater than 50 is it well now you have to give it
two options if this is true you’re gonna give it it’s gonna execute the first option if
it’s false it’s gonna execute the second option so since this is already in a print statement
all we have to do is add strings of text so if it’s greater than 50 put you are old and
how you separate the true from the false you add a colon not a semicolon that’s a regular
colon and if it’s false let’s put you are young so let me go ahead and run this and
let me show you guys what it does it says you are young in the run box and let me show
you guys why this is don’t mind any of this that’s not what we’re learning today what
it does is we asked it a simple question is age greater than 50 well you only have two
choices yes or no so then after you do this after the question mark you need to give it
what happens if this is true if H is greater than 50 and this is true we want you to do
this if it’s false then and it’s less than 50 then we want you to do this so again ask
you a question this is gonna come true or false if it’s true do this if it’s false do
this in that order and don’t forget this question mark and also the colon right here and remember
it isn’t a semicolon so that’s your real quick tutorial on how to use a conditional operator
and again this is um sometimes can be substituted for if-else statement but I’m usually gonna
be writing just basic if-else statements I just wanted to show you guys in case you come
across this you actually know what it is in aren’t loss so that’s it for this tutorial
thank you guys for watching make sure to check out my next tutorial and make sure to subscribe
to my channel so again thank you guys and I’ll see you next time what’s up guys welcome
to your 21st tutorial and in this tutorial I’m going to be building a simple application
to average a bunch of numbers together now we already learn all the basic tools but we
haven’t really seen how to combine them all and build a simple program so that’s what
I’m going to be teaching you guys in this story again what I’m going to be doing is
inputting ten numbers into the program and it’s going to give me the average so the first
thing we need to input numbers is the scanner so let’s go ahead and import it again that’s
dropping UT il scanner and this allows us to import the scanner but we also need to
create an object so we can use it after we imported it so let’s go ahead and make scanner
input you can name it anything you want a new scanner with a parameter of system in
and don’t forget our system in is the keyboard so that’s why we have that now that we have
a scanner we can use we can begin making the variables we need for this program so let’s
go ahead and make int total equal to zero and this is going to be the total of all the
numbers let’s say we’re inputting grades say we’re like a teacher in importing grades so
next we need another one called int grade and this is going to be the grade we enter
we have a next one called an average and this is going to be after everything is done we’re
going to average them all together so we need a variable for that and we also need the last
one that’s encounter and we’re going to set that equal to zero because we want to make
sure our counter starts at zero and I’ll show you what that counter variable is right here
when we’re building our while loop the counter variable is just on the counter for the while
loop so you’re going to say while counter is less than 10 so this while loop is going
to execute ten times on but what do we want to do ten times well since we’re importing
or inputting ten numbers we’re going to want to put grade equals input next excuse me you
need aa census object next int with empty parameters and what this does is this it allows
whatever number you input be stored in the variable grade so say you inputted a three
grade is now going to be equal to three but that’s not very useful unless we can add it
to the total so we can average it later later so now we have total equals total plus grade
and what this does is take that grade and add it to the total of whatever it was before
and if you’re saying all right how come you don’t just put total equals grade because
if you had um like 30 in this before it will now be equal to three and you want to add
it to that 30 so it would be equal to 33 so that’s what that does now you just need to
do spell that right counter plus plus and this will increment okay you’re cuckoo counter
each time so it actually goes through the loop so here’s what we have going on right
now we inputted a grade we added that grade to total whatever it was before and then we
added one so we can actually get out of this loop now we have a while loop what we need
to do is find the average of the total so let’s go ahead and write average equal total
over ten and we know that it’s ten because that’s how many numbers we entered and now
that we have our average calculated let’s just output it on the screen so system.out.print
line and let’s put something like your average is plus average so let’s go ahead and run
this and see how many errors I got and if nothing pops up in the run box then you know
you’re good to go so let’s go ahead and enter ten numbers one two three four five six seven
eight nine and ten and it says your average is five which it should be one through five
average I mean excuse me 1 through 10 average is 10 so let me show you guys one last time
how this simple program works this and this is just a scanner what you should know allows
you to input numbers you now have four variables the total holds the sum of all the grades
the grade allows you to import numbers individually average is going to be used later to average
them all together and this is just a counter variable for the wallet which you should know
what it does next you put input next in it’s going to be temporarily stored in grade and
it’s only temporarily because you change it with each loop this total keeps a running
tally of all the grades you entered so total equals the old total plus the new grade so
this gives you a new total each time that keeps adding and adding up after you have
ten grades entered you take the average of the total which is the sum of all the grades
and divided by ten and after all of that you just give the user a nice little prompt the
average is and it gives you the average so again this is how you can build a simple program
using the tools we have thus far and again you can add some if statements in here if
you want says if grade is less than four do this if grade is higher than five to that
bump we’ll get to that later I want to teaching you some more advanced stuff before that so
again that’s how you build a basic program I know you guys were it should build something
so there you go thank you guys for watching don’t forget to subscribe to my channel and
make sure to check out all my other tutorials and for all my latest Java programming all
that good stuff so again thank you guys don’t forget to subscribe and I’ll see you next
tutorial sup guys is Bucky and welcome to your twenty second Java tutorial and in this
story I’m going to be talking to you guys about for loop now the less couple tutorials
I’ve been going over a while loops and this was a different loop but a for loop is something
totally new so let me show you guys what the syntax for this is go ahead and type four
and as you can see it pops up in purple and that’s why you know it’s a built-in variable
or excuse me a built-in keyword and the for loop takes three arguments or three statements
inside it the first one is where you want the loop to start the second one’s where you
want the loop to end and the third one is how much you want to increment it by so if
you want to step one at a time or three at a time so let me show you guys you need three
you need to use the variable three times so the first statement you want to initialize
a counter variable and let’s go ahead and set it equal to one and this is because we
want our loop to start at the number one the next one is the same thing you did in a while
loop it’s the loop condition so let’s go ahead and put counter less than or equal to ten
so now our loop starts at one and it’s going to go until it’s less than or equal to ten
so it’s going to go until ten so next thing on we want to say how much do we want our
counter to increment by well we just want to go one two three four five six seven eight
nine ten so we want to increment it one at a time so it’s going to start at one as long
as it’s less than or equal to ten it’s going to keep going and we want you to go one at
a time so that’s the three parameters your for loop takes so now let’s go ahead and write
something in our for loop let’s just write system.out.print line and we’ll just print
the counter counter now let’s go ahead and run this see if we got any errors and we don’t
and as you can see down in our run box one two three four five six seven eight nine ten
and again this happened because it started at 1:00 our Cameron variable the next thing
it did is ran until it was greater or equal excuse me less than or equal to ten once it
got to eleven it says all right and my greater or excuse me in my lesson or equal to ten
no so I’m not going to do this loop anymore and then I incremented it one at a time you
can also increment it like something like three at a time by pressing plus equals three
remember we learned that in a one the previous tutorials now once you change the increment
instead of stepping by one it steps by three at a time one four seven ten the next one
is thirteen which is outside our condition so it proves false but again we can change
the starting point say we wanted to start it at six and go until let’s say twenty one
so now it starts at six and goes to 21 and steps by threes so let’s go ahead and run
this and as you can see 6 9 12 15 18 21 and then it stops so that is how you use the basics
of the for loop again it takes three um statements or parameters the first one is where you want
to start the second ones where you want to end or it’s going to run as long as this condition
is true and the third one is how much you want to increment by so this is a variation
um there’s also the while loop and the for loop we learned this far there’s also a couple
other loops that I’m going to be teaching you probably in the next couple tutorials
but for now play along with the prytt what’s it called play around there we go not play
along with it play around with a for loop until you get good at it and once you do you’re
ready to move on to the next tutorial so again thank you guys for watching make sure to subscribe
and I’ll see you next time sup guys welcome to your twenty-third tutorial and this tutorial
we’re going to be building a simple program so now that we learn what the for-loop was
I’m going to be building a program to calculate something called compound interest and this
is pretty much like interest if you put your money in like a savings account or something
you it will allow you to see how much money you have in future well I’m going to be using
it for is to see how many subscribers that I’m going to have in the future so right now
if you’re watching this tutorial and I’m making this one I have about 10,000 subscribers and
I figured out that I gained one percent of my subscribers each day so with that information
I’m going to be able to calculate how much subscribers or how many I’m going to have
in future so the formula for compound interest is this a which stands for the amount and
this is going to be what we’re solving for the future amount equals P which is the principal
which is 10,000 times 1 plus R and again R equals the rates and all of this is ^ where
the power of N and n is the number of years so we want to solve for a and what we need
to do is find P which is the principal 10,000 times 1 plus 1% to the power of n and this
the number of years so if this sounds really complicated let me show you guys how this
using a for loop and you will be substantially impressed I promise you so we need 3 variables
a double amount and we don’t know what this is yet so we’re just going to leave it set
to nothing double principal in again we’re using double because we want to use what’s
it called decimal points we can’t use int because these aren’t whole numbers we need
to use decimal points a double principle we know this is 10,000 since that’s how many
subscribers I have to begin with and don’t put the common there 10,000 so we have the
amount the principle and I told you guys the last thing they need is the rate so double
rate equals point zero one since I’m gaining subscribers at one percent a day so now that
we have the amount that which we’re solving for we have the principal the value that I’m
starting with and the rate 1% a day we can go ahead and make a for loop to build this
program so go ahead and all this for loop is going to do is say how long do you want
to run it for well let’s go ahead int and day we want to start with the first day and
we want to go to day 20 we can go to whatever we want just but less than or equal to 20
and put day plus plus and all this says is start on day 1 give me all the information
from day 1 to day 20 that’s all this does now let’s get the good stuff we want to solve
for amount so that’s what we’re going to be setting equal to since we don’t know what
it is yet but we do know what the formula is for it it’s principal and make sure you
type these right principal and again you need the time to spy something to the power in
this calls for an outside method that’s math pow now again you can see right here that
it takes two arguments the first argument what’s in the parentheses and the second arguments
the exponent so again let’s go ahead and add those arguments right here the first thing
what’s in the parentheses is 1 plus rate and what do you want to give the exponent year
or let’s see what it was day actually so now we have 1 plus rate which is a amount equals
principal which is 10,000 times 1 plus 0.01 to the day and that day is going to loop so
now all we have to do is print this out on the screen system.out.print line and let’s
go ahead and print a year actually day again whenever you use like a compound interest
and stuff you usually use a year but uh no one really uses day unless you’re you’re looking
at YouTube subscribers so that’s what I keep typing year plus and add a couple spaces amount
there you go so let’s go ahead and run this and I’ll show you guys what it does so now
we have a list down here that says how many subscribers I’m going to have each day so
on the end of the first day or after one day I’m going to have um 10,000 100 subscribers
that sounds about right that’s 1% and as you can see at the end of 10 days from now I’m
going to have 1146 subscribers and a couple half-half subscribers here and at the end
of 20 days I’m going to have over 12,000 subscribers so that is how you can build a program to
calculate something like investments or your mortgage payments or something like that again
let me show you guys how this works one last time as I always do we needed three principal
I mean excuse me principles we needed three variables because that’s how many variables
are in this formula you need to figure out the amount which we don’t know yet but we
do know the principal which is the starting point and the rate we want to set that amount
what you don’t know yet it equals the principal times 1 plus the rate which is 0.01 times
the day and this sort of the for loop comes in handy because this goes 1 2 3 4 all the
way to 20 and next we just output it on the screen so again um if you’re watching this
tutorial within Google on what the formula for compound interest is in you’ll be able
to follow along easier it’s kind of hard seeing in this unless you’re looking at the formula
but that’s pretty much how you calculate compound interest so um thank you guys for watching
my tutorial play around this and I promise after you do one time you’ll be expert at
it so again thank you guys for watching I hope enjoyed building a simple application
I don’t forget to subscribe to my channel and I’ll see you next tutorial so guys welcome
to your 24th java tutorial and in this tutorial i’m going to be teaching you the do-while
loop in Java now what the while loop did if you remember is ahead a test condition and
whenever that test condition was true executed the loop body but what the do-while loop does
is execute the body before even gets the test condition so you’re guaranteed to execute
the body at least once before you even check to see if you should be doing it or not so
the first thing we need to in order for me to show you guys how to do this is a variable
just make a variable called counter or something and set it equal to zero next let me show
you guys the syntax for the do-while loop go ahead and write du and then write something
to do in your body of your loop I’m just going to put system.out.print line and I’m just
going to print that variable counter but I’m going to spell it right and next I’m just
going to increment the variable counter so this loop actually ends and now after you’re
writing your loop body then you write the while condition so you want to do this while
your variable counter is less than or equal to 10 so let’s go ahead and show you guys
why this works as you can see in the run box it goes zero one two three four five six seven
eight nine ten oops so we had a counter that was initialized to zero and it did print it
out while the counter is less than ten if we’re saying all right this looks an awfully
lot Allah Allah wait a minute looks awfully lot alike there we go like the while loop
so if you’re wondering why is this even different let me show you guys it only does this loop
while the counter is less than or equal to ten so what if our counter was initialized
to fifteen or something like that well what it would do since it doesn’t check the condition
until after the loop is it executes this first so it would print out fifteen and then it
would see our a I’m only supposed to do this while it’s less than or equal to and so I’m
not going to do it anymore so let me go ahead and run this and as you can see in our run
box we get 15 so that is the difference between a while loop and the do loop anytime you want
to do something at least once you use a do loop anytime you want to test it first and
only run it if the test is true that’s when you use a while loop but again a do-while
loop guarantees you at least one run of your loop in a while loop only runs it when the
test is true so that is how you use a basic do combined with a while loop to form a do-while
loop that’s what it’s called so practice this and after a while you get good with it in
I’ll show you why it’s useful later on this rail wasn’t really a useful application but
this does have many uses in Java program and so I’ll show you why when we build applications
later on but for now just get familiar with the syntax with it and once you are familiar
with it you’re ready to move on to my next tutorial so thank you guys for watching don’t
forget to subscribe to my channel and I’ll see you next time what’s up guys is Bucky
welcome to your 25th java tutorial and in this tutorial we’re going to be going over
different methods in the math class now let’s see if it’s probably like tutorials ago when
I built a simple compound interest calculator we use one of the methods called power by
using pal and this allows us to use the power function but or our excuse me methods they’re
called in Java but in this one I’m going to be teaching you about other useful methods
so the first thing we need to do is go ahead and make a print line now on the screen so
print line and make it take an empty parameter for now and in this parameter I’m going to
be putting all the methods of the math class so go ahead and type math I’ll put your dot
separator and then the first one why say first first one I want to teach you guys about is
called the absolute value and that’s abs and inside your parameter it takes one number
now what the absolute value does is take any number negative or not and give you the absolute
value of it so if you have 26.7 and you go ahead and run this it would output twenty
six point seven this is pretty much if you have a positive 26 it would give you 26 if
you have negative 26 it give you 26 how much away from zero that this is so that’s what
abs does absolute value the next thing I want to teach you about is seal and this stands
for sealing any number you give it it’s going to round it up so if you give it a 7.4 when
you run it it’s going to round it to eight so even if it is really supposed to round
down the seven when you use seal it always rounds it up now since it has seal there’s
always something called floor again this takes a number say you have seven point eight it
always rounds it down so again seal always rounds up the number floor always rounds down
the number so your floor if you have seven point eight is going to be seven now that
we learn absolute value seal and floor let me teach you about something outs max now
this is the first one we’re in the less three we learned how to make a method that takes
only one parameter but max is the first one that takes multiple parameters in the single
method so what max does is you give two numbers and it gives you the maximum of those numbers
so say I have two parameters 8.6 and separate them with a comma in 5.2 whenever you run
this it gives you 8.6 because that’s the maximum of the two numbers so that’s how you can get
two numbers and find the maximum of those and again whenever you have a method like
that you also have the opposite and this one is called men what min does is take the lesser
of the two numbers so let’s run this and the lesser of eight point six and five point two
is five point two right down there so now we learn absolute value steel floor max min
again our power function which takes power and say you want something like five to the
third power you would use five for your first argument and three for your next one again
when you run this this was the same one we used in our compound interest calculator it
gets 125 since 5 times 5 times 5 is 125 and the last built-in method I want to teach about
in the math class is something called square root and sq RT that’s what stands for L only
takes one parameter such as nine and it finds the square root of that number so when you
run this in the square root of nine is three outputs three so that’s how you use um your
built-in methods from your math class again you want to notice that you don’t need to
create an object like you do when you’re making your own classes this is built-in so that’s
how you use math with your dot separator and then the method name and then put however
many arguments takes I just showed you guys let’s see absolute value zero for max min
pow square root I just showed you guys the seven probably most common ones and those
are the ones we’re going to be working with from now on so I just want to show you guys
what those do because we’re going to be using them and I don’t want you guys to get lost
so play around to those throw them in your built-in methods and you can make some pretty
cool stuff of those so for now I just want to show you guys that so thank you guys for
watching make sure to subscribe in my channel and I will see you next tutorial what’s going
on everyone welcome to your 26th java tutorial and in this tutorial i’m going to be building
a random number generator we’re going to be importing that from a class and i’m going
to be showing you how can use random number generators to you guess that generate random
numbers so let’s go ahead and pretend we were building a program so we could roll a dice
and whatever the outcome of dice it just outputted on our screen so whenever we want to use random
numbers we need to import something like we did scanner but this one is called a random
so go ahead put import java.util in the name for this is random well a smoker’s cough or
something so let’s go ahead and import random and now just like the scanner we need to make
an object for it so I’m going to name my dice you can name yours whatever you want and of
course that’s equal to nu naught R atom random with empty parameters so now that we got our
dice object we can use random numbers so the other thing we need is a temporary variable
called number it doesn’t need to be called number but I’m going to call it number and
this is going to store the number that outputs on the dice so for example it’s going to store
1 2 6 depending on what number you roll so I just don’t want to roll the dice once I
want to roll it 10 times so for that I’m going to need a for loop so let’s go ahead and put
forward in counter let’s start it at 1 let’s say well counter is less than or equal to
10 less than or equal to 10 and let’s increment it by 1 so now we have a loop that’s executing
10 times so now we got to give some instruction well since the number doesn’t have a value
yet let’s go ahead and give it a value now what you would usually do is use your object
like this number equals dice and then put your dot separator next in because you’re
getting an integer and then type in how many options you want it to have and since a dice
has options 1 to 6 I’m going to go and +6 right there now this would work right here
and let me show you guys what this does let’s just go ahead and system.out.print line and
this is a going to work fine so you can pay attention to this number plus and we don’t
need that other one right there so look good let’s go enough let’s run it and see what
it does it says 3 2 3 4 5 0 1 1 2 1 those look like a random numbers but the problem
is all of these random numbers if you couldn’t tell they go from 0 to 5 and why is that well
I’m about to show you guys right now whenever you use the sarandon number generator and
you give it 6 options the options that it takes by default are 0 through 5 if you use
6 again that’s 6 numbers but when it includes 0 it only goes 0 1 2 3 4 5 so what if instead
of 0 through 5 is your 6 options you wanted 1 through 6 which we do want since it’s the
dice and the dice doesn’t have 0 well what will you do in this case is simply put 1 plus
and then use our dice object to call this and what this does is it still uses the number
0 through 5 in this but adds 1 to them so what it does is give the illusion that we’re
getting the numbers 1 to 6 1 through 6 excuse me so now let’s run this again and we’ll see
what we get as you can see there’s no zeroes and you get 4 1 6 2 2 4 3 1 1 2 and all of
these numbers are in the range of 1 to 6 and that’s what we want so again if you want to
do this all you have to do is list however many numbers you want in your range and if
you put 6 by default it’s going to give you 0 through 5 since all computer counting starts
at 0 but if we want the numbers 1 to 6 we have to add this little 1 addition sign and
that takes 0 through 5 and adds 1 to them or increments um or pushes them all over by
one so instead of 0 through 5 you get 1 to 6 so that’s your quick tutorial on how to
import on the random class how to make a random object called dice and how to use that dice
object tag to a go fetch random numbers for you and also how to add one to give yourself
kind of a starting point so that’s how in slot machines or any program that uses random
numbers that they make that and we’ll be doing some more complex things with this but for
now I just wanted to give you guys the core basics of a random number generator and that’s
this so thank you guys for watching copy this code and play around with it and soon enough
there will be experts at it I promise so again thank you guys for watching don’t forget to
subscribe to my channel and I’ll see you next tutorial what’s up YouTube welcome to your
27th tutorial and this tutorial is on arrays now what an array is is pretty much a variable
that can store many values in it so um it’s useful when you want to have a variable that
has a bunch of related information and the thing about an array is that it can only store
values of the same data type so if you want to store a string and an integer in the same
array you can’t do that so the easiest way to explain what an array is is just to build
it and show you guys how it works and what it does so I’m going to do just that the syntax
for creating an array is simply first thing if the type in is what type of array you want
to create and I want to create an integer array to hold integers so go ahead and press
int the next thing you do is name your array and I’m going to name mine Bucky so it doesn’t
get confused the next thing you do is put square brackets and this is right between
the P in the backslash on your keyboard and this is just so the square brackets tell Java
that you’re going to be working with an array if you did this then it would just be a regular
variable but when you put the square brackets in Java knows all right you’re about to make
an array the next thing you do is set it equal to new since it’s a new array in again or
whatever type of data you’re going to store and square brackets the only thing different
is inside the second square brackets you need to put a number in there and this number indicates
how many values or how many variables you’re going to store in your single array so I’m
going to store ten variables or ten values and if you don’t know exactly what’s going
on I’ll show you right now so now we created array and it’s named Bucky and I told you
guys that you can store ten values in this single array name Bucky interesting all right
how do I do that well since we created a variable or excuse me an array named Bucky we have
something called indexes for that array and each index allows us to store a separate value
and those indexes begin with zero and go all the way to nine and again your computer is
kind of weird because even though you made ten elements doesn’t start one and then go
to ten and actually start zero to nine because your computer loves to start counting at zero
for some reason so our zero with element and Bucky which is our first element we can set
it equal to any value let’s set it equal to 87 so you don’t keep it fused next you go
ahead and make your next index or your next element of your array and set this equal to
some other value I’ll set it in quote 543 and you do this all the way until you get
to the last one which is nine let me just leave a couple out because I don’t feel like
typing them all and now once you did all of this and you set all your elements of your
array equal to value you can use those elements in your array and I’ll show you how to use
them let’s just go ahead and make a system out print statement print line might as well
all you can do in order to use this array instead of giving the variable name you just
give the name of the array and type whatever index you want to use so if I used Bucky 1
to print out what I do is say alright what’s the value for Bucky 1 543 let’s go ahead and
run this and look at our run screen 543 so that’s how you can use an array and again
an array is pretty much a single variable that can hold multiple values depending on
what you typed so for example we made this array able to hold ten value so it was able
to hold ten things I only made three right here because I was too lazy but you can make
zero through nine which will give you ten and again how you use it just read the name
of your array and then write this little subscript let’s go to index inside and that’s how you
reference it just like your reference a regular variable now if we say in our write an array
wouldn’t be really useful if we need type every single variable over and over again
well an array comes in handy let me get rid of this stuff right here one of the neat things
about an array is you don’t have to type ten variables when making your rate there’s another
way that you can do this and let’s just go ahead and get rid of everything let’s tighten
this up a little bit so she said another thing you can do is make something called an array
initializer and what this does is it initializes all your arrays without having to type the
array name subscript value array one subskribe array two sub subscribe gets hard to even
say so here’s how you make an array initializer go ahead and type what type of array you want
Bucky and again don’t forget the square bracket so it knows we’re working with array but instead
of typing new int n what you can do is just simply add those little curly bracket things
and go ahead and begin typing numbers in here two four five seven nine and what this does
is instead of having to tell on your array how many values will you want to store in
it it automatically counts how many values you put in and assigns a scut excuse me a
subscript to each one of those so instead of putting Bucky 0 equals to Bucky one equals
four Bucky two equals five Bucky three equal seven Bucky four equals nine it automatically
does that for you in this entire statement so now whenever we use Bucky and say we wanted
to use two again it would be Bucky zero Bucky 1 Bucky – so Bucky 2 would be equal to five
so let’s see if we got it right run it and as you can see it outputs the number five
so again this is a different way that you can create an array using an array initializer
I don’t even know what the first thing is called I guess it’s just called initializing
or creating an array or something but this is how most people do it in create an array
initializer and then you don’t have to go through the process of typing book e 0 equals
yada yada yada you don’t have to do that a million times all you have to do is type it
in a nice little list and it automatically does all the work for you and again whenever
you want to use one of your values or variables in your array just write the name of the array
in the number and again the number is called the subscript or index I’ll usually call it
the index or just number so that is your quick tutorial on arrays and how to create an array
in order also how to make an array initializer so I hope you enjoyed it practice this a little
bit in the next couple tutorials I’ll show you how to use arrays and programs and how
they’re useful and why they’re useful in applications so thank you guys for watching don’t forget
to check out my next tutorial and I’ll see you then so guys welcome to your 28th java
tutorial and in this tutorial I’m going to be creating just a basic array table to show
you guys visually the index and value of each array so let’s go ahead and just make a header
for our table using a system.out.print line statement and I’m just going to put index
and then put a tab and backslash T is just a tab it’s like five spaces or something I
didn’t feel like typing five spaces because I’m lazy just put backslash T then put some
value let me show you guys what this is real quick this gives you this index of value and
that’s the header for our table so now we have a header I can go ahead and list the
index and value of each array but before we do that we need an array of course so I’m
going to make integer array called Bucky and I’m going to use that a ray initializer that
we use last time and go ahead and add like five or six values or something at like 30
to 18 the 54 and 2 it doesn’t really matter how many values you add as you’ll see why
later on but go ahead and make an array and put some values in there doesn’t really matter
what they are or what how many you have next let’s go ahead and make a for loop to loop
through each index of our array so let’s go ahead and press 4 and we want it to start
let’s make a counter variable before I keep talking we want it to start at 0 because our
array our first index of our array is 0 even though it might have 6 elements in it or 5
the first one is the 0 with index and you’ll see why this is later on but and then the
next thing you want to do is give it how long do you want to go well as long as it’s less
than however you however many are in your array and this brings me to another point
every time you make an array your computer knows how many objects are in that array and
it stores it in something called the name of your array dot length and the only thing
that’s going to change in this is the first one whatever you named your array dot length
is would be in this case 1 2 3 4 5 so counter is less than 5 but for rate changes you don’t
have to change this so anytime you put your array name dot length that gives you the length
of your rate it’s built into Java it’s pretty cool function and now let’s just make it increment
by 1 and now that we have our for loop looping through five times beginning is zero we can
begin to use this so let’s go ahead and make a print statement out print line Die type
of right hopefully and the first thing we want to output is the counter and what the
counter is going to resemble is our index it starts at 0 and it goes to 4 0 1 2 3 4
and this is going to resemble the index so this counter has the exact same value is the
index next let’s go ahead and just put a tab because I’m too lazy to put a bunch of spaces
and now our last value we want to enter and this is going to be under the value tab of
our table we want to enter the value of the array so Bucky and in here we have the index
which is going to be counter so let me run this and let me show you guys what this does
hopefully I don’t have any errors and I don’t so here’s what it does as you can see we have
built a nice little table right here that shows us what index of our array is and what
the value is so Bucky 0 equals 32 1 12 and so on as you can see Bucky 0 equals 32 1 12
to 18 354 4 2 and that’s what this table did down here there you go now let me show you
guys or explain you guys one last time why this works the first thing we need to do was
create a header this is just so to make it look pretty pretty much the next thing we
did was create an array initializer and I tell you guys how to do this in the last tutorial
the next thing we did was make a for loop and key here is you need to start is 0 and
this is because your first index starts at 0 so that’s where we want this to start as
you can see right here index starts to 0 after that what you did is enter a maximum for how
far you want your counter go and your maximum depends on how big your array is and you can
get this by the special link thing I told you about and of course you want to go go
through it one at a time after that you just output it on the screen counter which was
the index which was cycled 0 through 4 this thing will just give you a bunch of spaces
in between and Bucky and then the counter inside it or the subscript inside it and whenever
you did this a reference say you reference Bucky 1 it will give you this value Bucky
to this value Bucky 3 Bucky 4 Bucky’s zero so that is how you build basic table to it
pretty much is just a nice visual so you can see the indexes and values of your arrays
so that’s pretty much all that does and I hope you understood that at least a little
bit so thank you guys for watching don’t forget to subscribe to my channel and hopefully I’ll
see you next tutorial what’s up guys is Bucky welcome to your 29th Jeff tutorial and I’m
going to make a real quick tutorial this time by a request I’m going to show you guys how
the sum all the elements in your array or to use all the elements in your array in any
calculation so let’s go ahead and in order to do that the first thing we need is an array
so I’m going to name mine Bucky as usual um I’m going to make the array initializer so
you don’t need to add the number it will do it for you say you wanted to average the ages
of people go ahead and write however many elements you want in your array it doesn’t
matter I’m going to have let’s see 1 2 3 4 5 people these would be their ages or anything
um once you have an array and I just use the object initializer or see the array initializer
go ahead and make a variable called a sum or some variable you can use to keep your
total of all your elements and and make sure to set it equal to zero because that’s what
you want to start out is the next thing we need to do was like last tutorial we need
to make a for loop and this is going to loop through every element in the array so of course
let’s go ahead and make a counter variable and since the first index of every array is
0 we want to start at 0 and then just do the little array length so what’s this Bucky length
and this will give you the length of this array that’s the trick I told you guys how
to do last time and then go ahead and increment it by 1 after this and you don’t really need
these curly brackets since it’s only one line but you want to take the sum and you want
to add um the previous number to it so let’s go ahead and do that and what this is going
to do is take whatever the value is and add it to the sum so its first it’s going to take
21 add to 0 16 added 21 86 added that 21 added that 3 added to that and it’s going to go
through and store all of these values add together in the variable sum so then once
we have all that all we have to do is output it on the screen so let’s go ahead and put
system.out.print line or whatever print you feel like using and then let’s go ahead and
write the sum of these modules felt like that numbers is and now let’s go ahead and write
our some variable and this should be it hopefully it works there we go and let’s go ahead and
run this and if it works I actually forgot to put space right there but the sum of these
numbers is 147 right there and again it displayed it like that because I forgot to put a space
right there and if I do it gives us our correct the sum of these numbers is 147 so that again
um to recap one last time go ahead and do your housekeeping like this what you do if
you want to use all these numbers in calculation then again you don’t have to get to sum you
can multiply them together or anything like that just take a variable and just loop through
your entire array using your for loop that I told you last time and use your little neat
little math trick that I told you before to in this right here this will loop through
each element in your array and get the value of it so that is how you use this neat little
summing of the elements of an array trick to get the sum or any other calculation you
want when looking at your array so thank you guys for watching hopefully now you know how
to sum all the elements in your right I hope to see you next time and don’t forget to subscribe
to my channel what’s up everyone is Bucky welcome to your xxx Java tutorial and in this
tutorial I’m going to show you guys how to build a program where you can take array elements
and store them as counters now we already build a little random number generator we
roll the dice and we store those numbers but in this program I’m going to make it a lot
easier and show you guys how to do it with an array so we’re going to be building a dice
rolling it like a thousand times probably in storing how often each number pops up so
of course we need a random number generator so let’s go ahead and import java.util random
and now once we imported that we can use it so let’s go ahead and put random I’m going
to call my object Rand and set it put two new random and we don’t need any ammeter rat
and now let’s go ahead and make a frequency array so just name it freak or whatever not
that kind of freak this kind and just set equal to new int seven now if you’re saying
alright there’s only six sides on the die why am I having seven elements in my array
well we’re creating seven elements because remember the indexes go from zero to six zero
one two three four five six since zeros include that seven elements in we’re going to have
an array index of zero and one to six that American use we aren’t going to use six I
mean excuse me we aren’t going to use zero but we need one two six so that’s why we need
seven elements so we can get one two six if we only created six then it would go from
zero to five so now we can go ahead and make a for loop to roll the die a thousand times
so let’s go ahead and put four and just put in roll equals one go start at roll number
one and put like roll if you want to roll a thousand just go put ahead and put thousand
and of course go ahead and increment them by one and again this just um loops this a
thousand times so you should know that but wait I want to teach you guys is this anytime
that rope up so actually let me go ahead and write the line of code first and then you
can see exactly what’s going on go ahead and take your frequency array and go ahead you
want to add one two something you want to go ahead and put your random number generator
in this and ours was named R and dot next int in of course we want let’s see six now
let me show you guys what this does this is the most important piece of code in this entire
program and let me break it down from the inside out this is going to give you the numbers
0 through 5 as you should already know what this one does is shift it all over so you
get the numbers 1 to 6 instead of 0 through 5 so if you’re saying all right what’s this
then what this does is add 1 each time that this hits that number so for example um frequency
1 2 3 4 5 6 are all set to 0 to begin with if this rolls in on the first roll it gets
a 3 then freak 3 is going to equal 1 if it rolls again in has a 3 freak 3 is going to
equal 2 if it hits again and again again 3 3 is going to equal 4 or 5 and 6 and it’s
going to keep count of all of the indexes and every time that it hits that number it’s
going to add 1 to that index so let me go ahead and well you’ll see what this does so
the first thing I’m going to add is a header so you guys actually know what’s going on
let’s go ahead and print line and let’s just print something like face the Nats head frequency
I don’t know if I spelled it right but it’ll do Pig that will do for and the last thing
we need to build is just something to output our data so the only thing we have outputted
right now is a header that says face frequency next we want to make a table to show you guys
face here is frequency so let’s go ahead and again we need to start at 1 or remember the
first number on the dice is 1 so face equals 1 and face let’s just have it less than freak
dot length remember I showed you guys that and a couple tutorials ago and just increment
it by 1 and now what do I want to do in this loop remember this loop is going to go 1 to
6 and it’s basically just going to make a sees me a table that has the list 1 to 6 so
I want to put system.out.print line not pront line can’t get it print line there we go finally
and let’s go ahead and go face because that’s going to be the first variable we want output
is just the face this is 1 2 3 4 5 and 6 the next thing we want output is just a tab to
give some spaces and then after that we want to output the value of each array index so
put your array name you’re right there and put your indexes right there so let me run
this program make sure I don’t have any errors and I’ll show you guys what we got we got
a table that says face and frequency and again we got that just by adding this face frequency
and then we have your array index number and your array value index number value index
number value in again if you’re wondering RA I know right here we created array with
7 and this equals 6 well actually your array index is start zero but we just wanted out
put on the table one because we don’t need zero for anything we could have added zero
right there and when you ran it it’ll give us this it would give us six to one and it
would give us zero but again since um this dice then it doesn’t have a zero we didn’t
use it so that’s why zero equals zero so now you can see um the number one rolled 160 times
the number two rolled 158 times and after rolling the dice a thousand times here’s the
distribution of all that so again let me talk to you guys one last time and show you guys
exactly what we did imported random number generator right here you guys know how to
do that we made an array called frequency and we set it equal to seven elements in that
array what we did right here was make a random number generator to roll the numbers 0 through
5 and we move that over so it rolled 1 to 6 any time I rolled one of those numbers it
took and added one to that index or that value in that array next we just made a header right
here and right here what we did is we just made a basic table we started it from zero
which we actually started at a 1 by just show the eyes we went all the way to 6 and this
just made a 1 to 6 and then we just outputted the value so again we outputted the dice number
which was the index number and the value so that is how you create a basic um using elements
and storing them as counters and array so it’s kind of confusing but just play around
with it and trust me you’ll get the hang of it so thank you guys for watching my xxx Java
tutorial there’s going to be a lot more to come so keep an eye out don’t forget to subscribe
to my channel and don’t forget to check out all my latest contests so again thank you
and hopefully I will see you next tutorial so that’s lucky welcome to your let’s say
thirty first draft tutorial and in this tutorial I’m going to be talking to you guys about
something called enhanced for statement now in the last couple of tutorials I showed you
guys how to use a counter controlled for statement to add up all the values in an array or just
sum them all together well actually Java made a very easier way to do this and they named
it an enhanced for statement so let me show you guys how to do it first thing we need
is an array and I’m going to name mine Bucky as usual I’m going to use my array initializer
and just set it to the equal to like four five six seven they’re real good enough now
let’s go ahead and we need another variable to hold the sum of the um array and you can
name a sum or total total whatever you want and now let’s get the good stuff the Enhanced
for statement now this is um kind of like a for loop but it’s different in a couple
ways it’s different instead of taking three options it only takes two different things
that it needs in the parameters or parentheses the first thing it needs is the type of data
and an identifier now this is kind of like a counter variable in your regular for loops
but it’s kind of different this is of course the kind of Daddy it takes no surprise in
the X what the X is is it’s going to store the values in the array as if slooping through
your array so the first time it loops through it’s going to store three then four then five
and six and seven and you just need a variable to hold all those values so that’s why this
is called the type and this is called the identifier next after that the only other
thing it takes is the name of the array now if we’re saying alright why do I have to name
this right in case you have more than one array in your program one name Bucky one name
tunafish one name dogwood it knows what array you’re talking about so now that we have our
for loop our enhanced for loop or for statement with our type identifier name we can go ahead
and do something with it so let’s just go ahead and take that total and set it equal
to X and what’s just going to do is it loops through is add these numbers to total each
time it loops so the first time it’s going to add 3 to 0 then 43 then 5 to 7 and it’s
just going to keep adding up till it gets the sum and eventually total is going to hold
the sum of all those numbers so now that total poses the sum holds the sum of all those numbers
let’s go ahead and just print out system out one print line there you go total now let’s
go ahead and just print it out make sure we don’t have any errors and we get the value
25 so let me show you guys what this did one more time we went in we made an array called
Bucky using an array initializer we then went and made another variable named total instead
of equal to 0 and this would hold the sum of our array next we made this special enhanced
four statement the first argument it takes is the type and identify what variable you
want to store the array values in next you need to say what array you were working with
what array you want to loop through and now you just did anything with those values and
we just decided to add them all to total to get the sum lastly we just printed it out
so that’s how you use enhance for statement and remember this is a force theme and that’s
specialized to loop through all the elements in your array so you can do something with
them so that’s that forest soil thank you guys for watching don’t forget to subscribe
to my channel and hopefully I’ll see you next tutorial what is going on everybody welcome
to your 30 second Java tutorial and in this tutorial I’m gonna be teaching you guys how
to pass a race in two methods now I tell you guys how to make basic methods and I also
taught you guys how to use simple variables and methods well a race can be a little tricky
so that’s what I’m going to teach you guys how to do this time so before we start passing
arrays into methods we actually need in array so let’s go ahead and make one again called
Bucky and just make your array initializer and put 3 4 5 6 7 might as well and that’s
that for now so now that we have an array we actually need to build a method to do something
to this so here’s your main method right now so go outside your main method and again make
sure you’re inside your class by outside your main method and go ahead and type public static
void and then name your method I’m just gonna name my change because I’m gonna want to change
my array now what you need here is the type and your local like how we built a variable
last time you wanted to do the same thing but instead of having just a variable name
you want to put those square brackets over it and that says that all right we’re gonna
be building the method here and it’s gonna take a parameter of one array so make sure
you name a variable which is actually an array and add those square brackets and that’s how
you tell that you’re giving me putting an array in here next go ahead and let’s add
something so we can put in our method that we just built so in this method what do we
want to do to change our array let’s just say we want to take all the values in our
array and add 5 to them just add something real simple so I can show you guys so just
add a basic for loop to loop through put int counter make sure I spell it right set it
equal to zero because that’s the first index counter is less than X length and remember
that’s built-in thing that Java knows and then just add one and let’s just put X counter
and plus equal five and what this does right here is it takes um all the indexes in the
array and adds five to each value of them so again you should know what this does already
don’t forget to put it in a separate method aside from your main one so now that we got
a separate method built and again the most important thing probably in this tutorial
is in this parameter in this method make sure to have an array instead of just a regular
variable so now back in our main method what we wanted to do is just call the method so
how you do this is put the method name and in your parentheses go ahead and write the
array name so mine is Bucky and again since Java already knows how long it is you don’t
have to put how many elements like four or five all you have to put is the name of the
array since this is Bucky with this many elements just put Bucky and it knows our matically
how many elements is supposed to pass into your right so now our array is changed so
we made an array we changed it so now we just got printed out on the screen so we can see
it so let’s use that enhanced for-loop that we talked about in the last Oriole and once
I get my parentheses my again this is called Bucky and let’s just put system.out.print
line and we’ll print Y so that should work I believe so let’s go ahead and run this and
as you can see the original array was three four five six seven and our new array is eight
nine 11:12 so it added five to the array which we wanted to do so let me show you guys one
last time what this does we made an array like we did a million times called Bucky three
four five six seven we next said alright take that array Bucky and pass it into the method
change or says alright where’s the method change oh it’s down here so I took that array
now what am I supposed to do to it Oh take each of the values in add five – alright I
did that now let’s come back here alright what do you want me to do next well just print
it all out on the screen and we know how to do that from last time so make an array change
it print it out on screen and again the syntax is a little different than making a regular
method so pay attention especially that you don’t need a number right here and also that
you need to define your array right here so aside from that it’s pretty simple so pay
attention to that play around with it and get good at it and then once you’re good you
can move on to my next tutorial so thank you guys for watching I hope you learn at least
some of this don’t forget to subscribe to my channel and I’ll see you next time what’s
up guys welcome to your 33rd tutorial and in this story I’m going teaching you guys
about multi-dimensional arrays now people make multi-dimensional arrays whenever they
want to do something like make a table in Java or make something where you need coordinates
so again or not again for the first time the syntax for making a multi-dimensional array
is your array type which is in it in this case first array this is just the name of
the array and instead of just one square bracket you actually add to the first one is for the
row and the second one is for the column so how you create this is this and this of course
is a multi dimension array initializer and this is the easiest way to create multi-dimensional
arrays so you pretty much have your main array right here once that I’m just filling it with
number four five six you actually fill them with other curly brackets where you can put
something like a nine ten eleven and then anytime you want to go to a new rope just
press comma and new curly brackets and put something like twelve thirteen fourteen fifteen
so what this would mean right here is you have an array with your first row being eight
nine ten eleven in your second row being twelve thirteen fourteen fifteen so whenever these
you want to call an element in your array the first row of this the first call is zero
so this would be first to raise zero one first array zero to like this first array zero one
that’s why I’m talking about when I say first of all one and this will point to this and
anytime you want to call something on your second row its first array one zero first
array 1 1 4 3 1 2 1 3 so that’s how you call elements in a multi-dimensional array but
what if you said alright I want to build a table but I want it to have different column
linked can I do that sure Ken so int second array let’s go ahead and create that and instead
of in your array having all the same row links what you do is this may be in your first one
you would put something like 30 31 32 33 and then in your second row you would have something
like 43 and then in your third row you have something like 4 or 5 6 so what this would
do is create a table with 3 rows 1 2 3 in the first row the columns would be 30 31 32
33 in the second row um it would only have one column 43 and in the third row down it
would have three columns four five and six so again how you would call or use the elements
in this array anytime you want to use this one the first number you would put a zero
and then put the number of the elements so zero zero don’t move that 0 0 0 1 0 2 0 3
this one won’t only have you would be able to call 1 0 and this one need to be called
2 0 2 1 2 2 so that’s how you call elements in a multi-dimensional array and actually
in the next tutorial I’m going to be building a program to output this so you can see visually
what I mean in how you create a table with rows and columns and once you see it it’s
going to make complete sense to you and it’s going to be really easy so that is the basics
of a multi-dimensional array again in the next tutorial I’m going to show you guys visually
how to do this so it’ll make a lot more sense to you so thank you guys for watching please
check out my next tutorial and I will see you then what’s up guys welcome to your 34th
tutorial in this tutorial I’m going to show you guys how to create a visual table with
our multi-dimensional arrays that we made in our last tutorial so let’s go ahead and
let’s just go ahead and make a whole new method to do this since it’ll be a lot easier and
go ahead and write public static spell it right void main and actually it’s not main
give it a name like display or something since it’s displaying your red and in your parameters
since is going to be taking in a multi-dimensional array just have it take one parameter in a
multi-dimensional array easy enough now in the body of this display method we’re going
to need to write two loops one loop is going to loop through the rows and one loop is going
to loop through the columns and actually the UM loop for the column is going to be inside
the loop for the rows so go ahead and write your first for loop and put in a row or something
so you can see that’s looping through the rows and just set that equal to zero and then
put Rho is less than X length or whatever you use up here and then just put incrementing
by one and now inside this for loop we want another loop to loop through the columns so
let’s put four and put int column pull u n n there we go equals zero since we want to
start at the 0th index then you want it to be let’s see column is less than X because
that’s what we passed into it row and then we want just the length of that so what this
would do is loop through on the exact length no more no less that’s a neat little trick
so anytime you’re making a for loop to do this inside instead of just X length because
you don’t want the length of that you want the length of the row so that’s how you do
this so and then just put increment by one CEO Lu men can’t spell column there we go
and this is your syntax for your inside loop set equal to zero have it go until the end
of the row and just increment it by one so now for the body of text we need for this
is we just want it to input or excuse me output the rows on the screen so system.out.print
make a simple print statement not a print line because we don’t we all want to have
it in a rows and we don’t want a new line every time where that would be a new row so
let’s go ahead and just print X row column and what this is going to do take the index
of row which is going to start at 0 and this is going to start at 0 every time and this
is going to print out our rows and so let’s just add a little spacer in between a new
tab and this would just give us some space between our numbers so now that we have another
row let’s go ahead and just make a new line so let’s put system.out.print line so here
is the end I forgot a semicolon right there so here’s what this method does the first
argument it takes is the row number and the second argument it takes is the column number
it loops through in and what this does right here is it just prints a row and what this
does is when you get to the end of the row it’s going to move down a new line so you
print a new row if I didn’t have this it would print everything all on one row and I don’t
want that so that’s why I added this so now we have a couple arrays and we have a method
to print out those erased let’s make sure I got my curly brackets and right there we
go should be good so now I have a race a method to print out those are race now let’s actually
call that method so all we would do let’s say I make a print statement so we see what’s
going on print line and just put something like this is the first array and to call this
what you would do is simply put display since this is the name of our method and you want
to pass it an array so let’s go ahead put first array and again you don’t need I spell
array with 3 R’s yes I did and again you don’t need to put any number of elements since it
already knows so next let’s just do our other one system.out.print line and then just write
this is the second array and then just display that to not the Splatt display second array
there we go should be good so now let me run this make sure it works and I’ll show you
guys and take note in my first array there are two rows the first row has 8 9 10 11 second
row has 12 13 14 15 and then my second row I have three rows with all different column
lengths so now if we look at this visually in my first array what sex ed firts array
spelled that wrong has 8 9 10 11 12 13 14 15 in this row and again that’s this in the
first row and this in the second row and in my second array let’s see what I got 30 31
32 33 4 values in the first row this one in the second row and 3 in the last row so again
that’s 4 1 and then 3 so that’s how you print out visually on your table in a multi-dimensional
array so let me explain you guys one last time how this works and hopefully this will
clear some things up we went and we had ahead and made some multi-dimensional arrays using
our two square brackets and kind of putting arrays in an array that’s what multi-dimensional
array is this calls the function or the method excuse me and what the method is or how it
works is this um this is just housekeeping stuff we wanted to pass a multi-dimensional
array so we make a multi-dimensional array we just named X so we can use it in our method
so the first thing we do this entire thing is a for statement right here and this is
loops through the rows or the first ones and inside that you need to loop through the columns
or the second one and then we went in head and just printed it out with spaces in between
and once we got to the end of a row we just printed a whole new line so that is how you
do that and again what we did right here was called making a visual table using a multi-dimensional
array so again just copy exactly as I did and once you type it for yourself you’ll understand
a lot better but for now that’s all I got for you for this tutorial in the next tutorial
um I’ll probably do something a little bit easier but just as useful so thank you guys
for watching I hope you subscribe to my channel and don’t forget to check out my next tutorial
sup guys welcome to your 35th java tutorial in this tutorial I’m going to show you guys
how to make a variable length argument list now I show you guys how to build methods using
multi-dimensional arrays and also I’ve built basic methods but each time you did you needed
to tell it what arguments it took but sometimes you want to build a method and you don’t know
how many arguments took so for example say you want to build a method to average a bunch
of numbers well maybe you don’t know how many numbers you want to average first so you don’t
know how many arguments to give it well and this is where I’m going to show you guys how
to make a method that takes however many arguments you want so let’s go ahead and go it a method
outside our main method let’s build a public static int sense is going to be returning
injures average and I just named average you can name it whatever you want now go ahead
and it’s going to take an argument of integers but you don’t know how many so anytime you
don’t know how many what you do is put in the lips and that’s three dots and then put
the name of the variable you want to use and instead of putting in x and y and z you just
put three dots in what three dots means is all right I’m going to be throwing numbers
in here but I don’t know if I’m going to throw two numbers five numbers or 500 numbers so
dot dot means just do it and I’m not going to tell you how many numbers so now that we
have that that’s a new thing I wanted to show you in this tutorial dot dot means you don’t
know how many arguments is going to take let’s go ahead and build a simple function let’s
just total all these numbers so it starts at zero since we don’t have any numbers yet
let’s make an enhanced for-loop set our variable equal to X and it takes numbers in it and
let’s just add all those numbers to the total so total plus equals X so it’s going to loop
through all those numbers and add them all to the total so now after that we just need
to return the average so returned total over numbers the length so what this does if you
through five numbers in here it’s going to return total divided by five if you only threw
three numbers in here it’s going to return that total divided by three so number what
should actually be numbers is what you passed in within the length of it is how many values
so that’s how that works so this is our method we just thought now we need a way to output
on the screen so go back to your main function so you can run this program and just write
system out mu my mouse print line and let’s just print something like um average and then
in here in your average method you can type however many numbers you want 4356 76 and
eight and let me go ahead and run this and show you guys the average of this is 45 so
that took um four arguments or four numbers right there but let’s say we wanted to add
more 6576 to and thirty-one let’s go ahead and run this does it still work yep interestingly
enough the average is only forty four for this interesting so this is what this does
anytime you want to build a method this is the meat of the story all right here anytime
you want to build a method that you don’t know how many arguments it’s going to take
so for example we pass like for the first time in eight the second time what you want
to do is put what type it is the ellipse and then you just give yourself a variable that
you can work with in your method so again that ellipse right there means I don’t know
how many it is so you don’t have to make it over and over again so again we just built
the method right there and called it in our main function right there so that’s your quick
tutorial on how to make a variable length argument list in methods that you build so
you don’t have to write um a new method each time one and enter a different number of are
you um so practice that and once you play with it a couple times you’ll get good at
it so thank you guys for watching don’t forget subscribe to my channel and don’t forget I’m
going to have this video able for free download so make sure you do that if you want so thank
you guys for watching now see you next tutorial sup guys welcome to your 36th Java tutorial
and in this tutorial I’m gonna show you guys how to build a time class now what time class
is is it’s pretty much a separate class that has a bunch of different time functions and
I’m going to allow the users to enter three numbers one for the hour minute and seconds
and it’s going to convert that in military time and regular time and we’re going to be
needing this information for a next couple tutorial so make sure you build this with
me so first let’s go ahead and our tuna class right here make sure you’re outside your main
class and I’m going to go ahead and build three variables and they’re going to be private
variables so not private private same thing right and make sure they’re integer variables
one for our and another one for a minute and another one for a second so just copy that
because I’m lazy and turn this one a minute and turn this one a second so now we’ve got
three private variables but now they have no value so what we want to do is give them
a value and we’re going to do that by letting the user input the numbers so let’s go ahead
and make a method to do this so public void since it’s not going to return anything it
just named a set time or you name anything you want but this is also going to take three
arguments in H for our and M for minutes and in s for second so it’s going to take three
arguments but we just don’t want to let them enter any number they want since the hour
has to be between 0 and 24 the minute has to be between 0 and 60 since that’s how many
minutes are an hour and the seconds also have to be between 0 and 60 so what we’re going
to do is check this data before we enter it so let’s plan our is equal to and instead
of just H let’s go ahead and check it so let’s go ahead and write let’s just do this Wow
would you look at that if our is less than or equal to zero and you have to make a hand
because it needs meat to conditions and my ampersand is on seven I put a bunch of stickers
on my keyboard for After Effects so now I can’t see them as symbols I have to look at
my laptop for it so and now if our is less than 24 so if it’s between zero what the heck
just happened there I’ve caps lock on our sum no just a funky little thing all right
now our is less than 24 there we go a mess up that time so if these two conditions are
met and the question mark are these two conditions met then our if not zero and why is this little
green bar right here there we go must’ve been something with my screen recorder so here’s
what we’re seeing right now if our is greater than zero and it’s less than 24 then you can
go ahead and use that number if it’s not then go ahead and by default just put zero so we
don’t mess up our whole program just because they entered a wrong number so now we need
to do this for min and second so let’s go ahead and change minutes and changes the m
and change this to M in this to M and then go to guess what we’re going to do next second
it changes the s and this s and this test and make sure this hms matches whatever you
put up here and now don’t forget to do this instead of 24 go ahead and change these to
60 I know you got to change all this it probably would have been faster just to type it by
hand but well we didn’t so too bad so now that we got them to enter a time and what
this is going to do when we call this method right here they’re going to enter three numbers
is arguments so what we want to do is repair must set the time right there but we have
no way to display it so the first way I’m going to display it is through military time
so and that’s the time where you don’t you can use like 12 to 24 so you’ll see what it
is later so public string since it’s going to return a string since it’s going to display
something obviously to make sure I had to spell military right and it’s going to take
no arguments so I’m just going to display and in the body I’m going to return string
format and remember our format takes two arguments oh the added appointment for us how kind delete
those kind but not kind enough would you fill in the rest of it for us it’s going to take
and remember in here you need to put percent and where’s my % above the 502 d : % o 2 D
: % o 2 D make sure I got that right and what this is going to do is display the first one
in two decimal places and then add a colon display the second number two decimal places
then add column to display two seconds at two decimal places and after that let’s just
go ahead and add what we want to put in our minutes second and now that they’re set right
here we can display them down here so now just add a colon after that and now we built
everything we need to do so now we can go to our main apples method right here or Apple’s
class excuse me and we can begin building our objects since this was the tuna class
we need two tuna object for that so tuna tuna object and remember you need a object so you
can use the crap inside the class so equal new tuna and first let’s just go ahead and
even though we didn’t set a time yet we can go ahead and display the military time just
see what it has for default so system out and let’s just go ahead and print line and
put tuna object – or was it to military there we go to military and so we didn’t set a time
yet so whenever we run this make sure I don’t have any X’s anywhere it should give us all
zeros by default so yeah save those and look that by default we get all zeroes right here
so now now that I lost my screen recorder oh man hopefully it’s somewhere in there whenever
I run this program my screen recorder goes behind my java so I have no idea what’s going
on right now oh oh well anyways that’s really annoying but anyway so let’s go ahead and
set the time now so tuna hopefully you guys can see this object and now we can go ahead
and press set time and of course this is going to take three arguments and let’s go ahead
and press something like 13 for hour and 27 for minutes and 6 for seconds and now once
you run this system out well we can just go ahead and copy this since real lazy copy once
after we set it we can go ahead and run this again and hopefully if I don’t have any errors
we can go ahead and see right here the first one was zero that was before we set the time
and the second one when we set the time right here 13:27 6 what that did is converted all
to military time and now I can see my screen recorder but still behind so now do my screen
recorder is messing up got to remember fix that somehow so now let me show you guys what
we did in our set time 13 27 and 6 we weren’t right here passed these in right here 13:27
and 6 I checked if 13 was between this it was which sect if 27 was between this and
6 was between this since it was it used all the values and set them in an hour minute
and second and that was when we put print to military pretty much a display method it
pretty much just put them in this format and displayed them out to us as you can see here
so in the next tutorial I’m gonna be showing you how to use not military time regular American
time or I don’t know what it’s called just regular time I guess so um thank you for watching
in the next tutorial you definitely want to watch because we’re going to need that information
probably for next couple few tutorials so again thank you guys for watching don’t forget
to subscribe it and now see you next time what’s up guys welcome to your 37 java tutorial
and in this tutorial I’m going to show you guys how to use our time class to convert
time to a regular string instead of military time since you know not everyone uses military
time some people just use normal time like 1:30 p.m. so let’s just go ahead and I’m going
to show you guys how to do that so we first need to make another method and I’m going
to name mine public but I’m going to spell it right eventually there we go right there
you got a buddy public string and let’s just name it two strings just a normal string you
can name it like two normal or something if you want but you know what I don’t so I’m
going to name mine to string and now we got a new method bill and what we wanted to do
here is just return a basic formatting string so let’s go ahead and return string just like
last time move my cursor earlier format I’m I’m not typing to right today and now once
you do that it’s going to let us format the string how we want it so the first thing that
we need to do is make sure I don’t get anything mess up string format looks good first thing
we need to do is give the format we want to put our time in so for the first one for the
hour we just want percent d for the minute we want percent o to D so percent zero to
D and this is because the minute always has two decimal places for the second it’s the
same one percent o to D or zero to D excuse me and for the AM or PM we just want to string
since they’re just letters so now for the hour we need to do something weird we need
to check if it’s zero or 12 then put 12 if not then put the whoa you’ll see what we do
so in here go ahead and in your well just do as I type if our is exactly equal to 0
or if our is exactly equal to 12 then what do we want to do well let’s just go ahead
and put 12 for that if not else if it isn’t then just go ahead and put our modulus 12
let me go slide this over a little bit maybe that will be easier for you guys so what we’re
doing here is saying all right if that if they put 0 or 12 for the hour then go ahead
and put 12 if they put anything else then divided by 12 and give our remainder so if
it’s 13 put 1 if it’s 8 by 8 if it’s 14 put 2 simple enough that the other ones are a
lot easier I promise for a minute we just need to go ahead and type minute since we
don’t need to do anything special with that second just go ahead and type second since
minutes and seconds don’t have a a.m. or p.m. only hours do so now it brings us to my last
point we need to check whether it’s a.m. or p.m. they’re talking about and there we go
right there so how do we check if it’s a.m. or p.m. well we need to test the hour first
of all and if our is less than 12 then what do we want to do we want to go ahead and insert
a.m. else if it’s not let’s go ahead and insert p.m. so that’s how we check for a.m. or p.m.
right there so now we got our basic two string and we got a little error right there and
I forgot parentheses somewhere right here I’ll find it I promise I will I think I did
crap this darn screen recorder is in the way let me pause this off here we go this is the
one I forgot right here again when you’re doing your hour make sure this one’s enclosed
right here and make sure the entire thing is enclosed right there but anyways hopefully
I don’t have any more errors now that we got our basic string to string method built we
can go ahead and call it in our main function so let’s just go ahead and right here we called
the military one and we can go ahead and copy this and we’re not going to use it again I’m
just too lazy to type to string so the first one is going to call the military time the
second one is going to call the string one that we just built and by default this is
zero and by default this is 12 and if you’re saying alright why isn’t this zero and why
is it 12 well I’ll show you right here and right here where we put if our is zero or
12 and then put 12 and it was zero so put 12 since when you’re looking at regular time
there’s only 12 o’clock then it goes right to one o’clock there is no zero o’clock I
don’t know if you guys knew that or not but uh yeah drop that in your notebooks there’s
actually no zero o’clock so now let’s go ahead and quit messing around this crap and do what
we came here for we want to be able to set the time so let’s go ahead and put tuna actually
probably want to put tuna object and let’s go ahead and use our set time function and
we want to editor enter three parameters the hour and we’ll go ahead and change that to
13 which should be one o’clock in regular time and then for minutes we’ll put like 27
and then for seconds we’ll pull like six or something then go ahead and add a colon and
now we can go ahead and output these two again and why type them again if you can just copy
and paste them the lazy way that’s right that’s what I’m talking about and now let’s just
go ahead and well let’s just go ahead and output it simple as that so here’s what we
got here is our defaults that we got from last time before he set the time and then
we set the time in military time it was 13 o’clock on him 1,300 hours 27 6 seconds in
regular time is 1 o’clock or 127 and 6 seconds p.m. so that is how you use here let me recap
this one more time what we did is refer much as output the defaults on screen then we went
ahead and called set time passing the parameters 13 27 and 6 so duck took 13 hours and converted
it to hours was the next one 27 and stored it for minutes and 6 and stored it for seconds
outputted that in our military format outputted that in our regular string format so that
is your basics of your time class right there and make sure that you are copy all this and
follow along with me because in the next tutorials I’m going to be teaching you a new stuff not
about time but we’re going to be using this code right here so make sure you copy all
this and make sure your programs are working and if they aren’t then leave a comment on
this video and I’ll try to answer it for you so thank you guys for watching don’t forget
to subscribe I hope you learned a little something but not too much and I will see you next time
sup guys welcome to your 38th java tutorial and in this tutorial I’m going to show you
guys how to control access to different variables in other classes and also what the this keyword
means in Java so let’s first of all talk about access to these private variables right here
now what private means is that these variables are private meaning that only these methods
have access to it only these methods in the same class this tuna class can use these variables
so what if we try to use these private variables in another class like our apples one well
let’s go ahead and try to do that right now first of all we already made a tuna object
to use all the stuff in that class but let’s go ahead and try to use something like our
right here if we go ahead and try to use our and change it to like another number we get
this little um error right here in a freer to run this would get a compilation error
so I don’t want to do that so what it says is the filled tuna hour is not visible and
that is because instead of public it is private again meaning that only these methods right
here can use it so if we want to change that and put it so these variables can be used
in any class outside we need to change that to public and now you can see my little X
went away so now I can use the class outside to change the variables in another class so
let’s go ahead and change it back to private and make sure you spell it right that’s kind
of important and go ahead and delete this and that brings me to another point what the
this keyword is in Java so what if you’re saying that all right I got three variables
in this class name hour minute and second but also in my constructor in or if this doesn’t
even matter it can be your constructor or just another function or excuse me method
I’m in talking about C++ for too long changes the hour minute and second so now probably
need to change these two don’t you think minute and second so what if we were to say that
these variables in this method inside this class we’re the exact same as these variables
right here so in other words if the constructor or any other method uses names or variables
identical to instance variables then what when you run the program what’s it going to
do well let’s go ahead and see right now um I guess we don’t need this anymore but we’ll
keep it anyways let’s go ahead and run this and as you can see we get one two three one
two three and then we set the time which doesn’t matter anymore then we get one two three one
two three so my point is that is this anytime you have the same variables and a method or
constructor or the same thing um you Java looks to these variables the local variables
instead of these right here so retain all right that’s good at all and by the way you
should never name these variables the same as this this is just a foreknowledge but um
anyways so what if we want to use that these variables of four or five and six instead
well if the method contains a local variable with the same name as the field names right
here then the method is always going to look at the local variables instead it’s always
going to look at these instead and that is there is only one way to kind of overpower
this and that is the use of this reference to refer to these variables instead so for
example you know we had one two three one two three one two three one two three well
if we use a little keyword called this instead then it’s going to refer to these variables
so this our this and this second and this pretty much means this method right here that
we’re talking about so anytime you use this it says all right don’t use all these use
this right here and I’m sure that’s a tone when he was creating this use this one right
here I’m sure he said that so now if we go in our main apples program and go ahead and
run it we now get one two three one two three before oh four five six four five six so that
is using these local variables instead of these private ones right here so again any
time you want to use the variables in your method instead of the variables outside your
method if they’re named the same thing you need to use the this keyword and that says
alright use these ones right here or use this one’s not here that doesn’t even make sense
but you know what I mean use them locally instead of far apart so again it’s easier
just to see and play around with it and once you do you’re going to understand what this
means Wow it’s like a little joke and anyways I hope you understand at least a little bit
in the next tutorials I promise I’ll be clearing the software is kind of confusing right now
but um keep an eye out for my next tutorials don’t forget subscribe and I’ll see you next
time what’s up guys welcome to your 39th job tutorial and in this story I’ll be talking
about overloaded constructors now you guys already know what a constructor is it’s pretty
much a method with the same name as that class and whenever you create an object it automatically
calls that method or does that method so I told you guys how to build a constructor and
I told you guys that you can build only one constructor with the same name as the class
but I didn’t tell you guys that you can build multiple constructors in depending how many
arguments you have it picks what constructor to use for example if you called that object
with one argument it would have a constructor for that if you call it that um object with
three arguments it would have a constructor that took three arguments so let’s go ahead
and do this right now so we first need our three variables private int hour and then
we need that same thing let me put a semicolon instead of colon we need that same variable
with minute and second minutes and second now let’s go ahead and build our first constructor
and we do this by putting public tuna since tuna is the name of the class and I’m not
going to have any arguments for this one we’re going to do one with zero arguments one two
and three so when you put one with zero arguments what we want to do is eventually we want to
give it three arguments so what will you do is put this keyword and what this does was
is pretty much invoked the constructor again but give it three arguments this time using
0 0 and 0 so now we need to build another constructor so public actually we can probably
just copy this copy Relays E and paste public tuna but instead of zero arguments this one
if they pass in one argument what are we going to do well if they pass and one number then
let’s just assume it’s the hour so we put this hour so if they passed in object five
it’s going to be five o’clock than zero zero so now let’s build another one and this one’s
going to have two arguments this one’s going to have an hour and minute so int hour and
minute right there so now what we want to do is invoke hour and minute and again what
this is going to do is call this constructor again but pass it three arguments right here
so now I have person all right if we call this constructor again it’s going to look
through this one see where is there’s three arguments that look through this one see where
do these three arguments and look through this one see where the story arguments and
that’s why I’m getting X right here it says the constructor tuna in it is not to find
because we keep calling a constructor with three arguments what we didn’t build one yet
so let’s go ahead and build one right now let’s go ahead and put public tuna and I could
have copied that but in our in minute int second and if you watch all my X’s just disappeared
so you see there now up and then once we finally build on it disappears so now that we have
a constructor with three arguments we can go ahead and build something what it does
in fact I’m going to build another I’m going to have it call another method right here
that sets the time to our minutes and seconds and we’re actually going to be building this
and the next tutorial actually we can prep a builder right now we have enough time but
let me explain you first what this one does if a user was to create an object with zero
arguments it would give it three arguments by default so it can go down here to this
constructor if a user was to enter an object with two arguments it would go to this one
it would use the first number is the hour the second one is minute and the third one
is zero and then it would call this constructor again with three arguments and the only one
with three arguments is this in our in minute is second and then what this constructor does
is set the time in a set time you’re saying all right where the F is that method well
we’re going to vote it right now so take it easy let’s go public void set time and as
the arguments again what we want to do is take three parameters an H into m per minute
and into s for seconds now in the body scroll up a little bit there we go not bad and the
body what do we want to have to set the time well actually we’re going to be building three
methods for this as well and I know it gets confusing but set our and this is going to
take an hour set minutes and this is going to take a minute and set a second and this
is going to take a second parameter and now once you close this it says the method set
minute is undefined and we’re actually going to build three I mean let’s see six more methods
I think we’re going to build methods for setting each of the times and why do we need a new
method for set our new method for cent minute and set second well we can’t just have any
hour they type in um we need to build a method for it like last time where we set the hour
we had to check if those between 0 and 23 or 24 and set minute we need to make sure
this is between 0 and 60 and also for set seconds and we’re also going to make make
another method for a get method I mean I not get method for get our get minute and get
seconds and that’s just going to return everything but we’re going to be doing that next tutorial
but if you don’t still don’t know why I’m having set separate methods for these it’s
so only these methods can access the hour and down here as I said in last time we don’t
want any other class that have access to this information right here so that’s why we need
to build a separate set and get methods for each hour in um like hour minute and second
but anyways that was supposed to be for next tutorial that was just a little jump ahead
the meet of this tutorial that I want to tell you is right here um let’s see yep these are
all constructors right here one with zero arguments one with one two and three and I
just want to tell you that you can build a different constructors depending on how many
arguments you have that way you don’t really need the user to enter one specific set of
information it varies and then depending on how much information they entered it does
a certain task so if you don’t understand this I promise in the next on either one or
two tutorials this will make all sense once we finally build our program and you can see
what’s going on but thank you guys for watching make sure to write this code right now and
again like I said by the end of these tutorials you’re going to understand why we did it and
how this all works but for now thank you guys for watching my tutorial on overload constructors
don’t forget to subscribe to my channel it is the best channel ever again thank you guys
for watching and I’ll see you next time sup guys welcome to your 40th java tutorial and
in this tutorial we’re going to be building the set our set minute and set seconds methods
now we already got the data from the data that we need in the last story so hopefully
you watch that because you need this code anyways but if you did and typed everything
up then that’s good you’re good to go so let’s go ahead and build first the set our function
or excuse me method the same thing as function pretty much I just spent on around C++ all
day so anyways public void since it doesn’t return anything and sets our and what arguments
is take in H it takes just the hour since again we’re only setting an hour nothing else
now in this what we want to do is check if the data is between 0 and 24 and if it is
it’s valid if not we’re just going to set it to default like zero or something and by
or something I mean 0 so let’s take that hour and first let’s make a simple if statement
is the hour greater or equal to 0 and where’s my add 7 right there again I put stickers
on my keyboard so it’s kind of annoying and is the hour less than 24 you’re going to say
all right if that is true then you can go ahead and use the hour else if it’s not true
go ahead and put 0 so again this is a conditional expression or um it’s pretty much the same
as an if statement what this is going to do is check if the Hauer is between 0 and pretty
much make sure that hours greater than 0 and less than 24 and if it is use it if not use
0 so now do the same thing for minute and second except when we use this um we want
to change our minutes and seconds and we also want to change this minutes and seconds and
we also want to change this minutes and don’t use a capital and second and also on changes
minutes minutes second second and instead of having let me check the sub data real quick
in minute minute minimum in it instead of having 24 you want to change these to 60 since
with minutes and seconds it doesn’t need to be between 0 to 24 it needs to be between
0 and 60 so that’s why we do that so now that we’ve got our hour minute and second built
what’s this a right here to get methods second hour and type 2 that’s good we’re good to
go hour minute second what we need to do this is what Oh saner here sets minutes and set
second so then now that we got our check for hours our check for minute and check for second
what we can do now is write get methods just to get them since we write a set method to
change data if need be if it’s bad and we need a get method to pretty much when we’re
retrieving our data um this is what we need this method for so let’s go ahead and write
public int and the first one we want is get our so get our and this is going to take no
parameters and what it’s going to do is this is the easiest thing you’ll do all day get
returned hour right there so what this is going to do is pretty much take this and return
it so let’s copy this and keep up with me it cuz it’s going to be a little too easy
get minutes and this one’s going to return a minute and get second and this is going
to return a second so now that we have three set statements in three get methods I mean
set methods get methods we need one more method and I pray this is the last one the last method
that we need is pretty much just a formatting method and this pretty much just spits it
all out or display method so like last time I’m going to put public string since this
is going to return a string and after string I’m just going to name it output like two
two military times it’ll do military time military time is a lot easier than normal
time and this isn’t going to take any parameter since you’re just going to return string so
what we want to return is let’s go ahead org string format and again it tells us we need
two arguments in the first argument is let me get rid of this as annoys me the first
argument is how we want to format so we want to format percent zero to D percent zero to
D : percent zero to D so percent zero to D percent is your T % zero to D and this means
the hour the minute in the second is each going to have two decimal places so for the
first one for the hour it says what number do you want to use well we want to use whatever
number was returned in our get our method right there for our second one for our minutes
we want to use whatever was returned and our get minute method right there and for our
last one of course get second right there so now these functions let me double check
this make sure it’s good these functions are good to go we built all the methods that we
need and again whenever I say functions I really mean methods I’m just uh just another
language those methods are all we need so now we can go in our main apples class right
here and we can begin building our objects now again whenever we’re going to go ahead
and create four different objects because we had four different constructors and actually
I’m going to be doing that in the next tutorial so as you can see we have one constructor
two one two three four so in the next tutorial I’m going to be putting four different objects
each to use these constructors in four different ways and then I’m going to be summing up and
telling you how this whole program works and actually what the heck we just did and then
you’re going to understand that awesomely so thank you guys for watching don’t forget
to subscribe and now see you next tutorial what is going on people welcome to your let’s
see fifty first Java tutorial I believe and in this tutorial we’re going to be talking
about GUI some more and unlike last time where we built a GUI that looks the same on every
single operating system like if you ran on a Windows operating system and a Mac it will
look the exact same what we want to do is we want to build an interface that when you
run it on a Windows machine that it inherits all the look in the feel of a Windows program
and when you run on Mac machine that uses all the buttons in two bars and title bars
and windows as a Mac so the last one we built in the last tutorial was simple for like you
know a really easy one but we’re going to be going in some complex and it’s just a better
GUI system of building interfaces so that’s what I’m going to be teaching you today so
the first thing that we’re going to want to do again we’re going to be working with two
classes the apples main class with our main method in it and a subclass or another class
called tuna right here so in your tuna class or not the one without your main argument
the first thing we’re going to do is import a bunch of stuff to use so the first thing
we’re going to import is go ahead and type import java.awt dot flow layout and make sure
you’re capitalized like I am and what this is going to do is it’s going to import pretty
much how things are placed here that’s how I can say it what this is going to do is pretty
much give me the default layout managing it’s going to say alright I’m going to put this
here when I build my next item put it to the right of it when I build my next item put
it to the right of it and once you run out of space just move to the next line so this
is pretty much the layout of our thing and we don’t want to have to program an entire
layout so that’s why we’re importing that the next thing we’re going to want to import
is go into import Java X don’t forget that X and we’re going to import swing dot j-frame
in there we go what jframe is is it pretty much gives you all the basic windows features
like the title bar the minimize the maximize the X to close and it pretty much just gives
you the basic window so we don’t want to we want to use what we have already so that’s
why we’re importing that and the last thing we’re going to import in this tutorial is
the J label and this is where we’re going to be building in this pretty much a label
is pretty much just a line of text the N it also lets you do simple images but let’s go
ahead and import Java X again swing the J label make sure it’s capitalized just like
that so again this is gonna there sorry about that I had to take a little break someone
knocked on my door but what J label does is it allows you to output text and images on
the screen so that’s why we need to import that so now we can go ahead and start programming
this stuff right here the first thing we want to do is use inheritance like we did before
public class tuna extends ext NDS J frame so we need this tuna class right here to inherit
all the stuff from J frame and again like I said J frame gives you all the basic windows
features so now we have all of the title bars the minimize the maximize the X button that’s
what that does now that it’s in here it inherited all those qualities let’s go ahead and the
first thing we’re going to want to do is build a variable which is pretty much going to be
our item so let’s make it private and let’s just go ahead J label that’s what type it
is and just name it like item 1 or something like that and this is pretty much it’s going
to be the item that we’re adding I mean you need to name it something so why not item
1 and now we’re going to build a constructor so go ahead and type public tuna or whatever
your class name is and give it empty it’s not going to take any parameters and the first
line in our constructor and I spell – nor on the first line in our constructor is the
title of the window so let’s go ahead and how you do that is you put super and the only
argument it takes is the title so this was going to be your in title bar though the title
bar let’s just go ahead and put that so that is how you add a title to your window the
next thing we’re going to want to do is set the layout which is pretty much the default
layout so go ahead and put set layout and all of these methods unlike super and set
layout these are imported whenever we imported everything so set layout and as a parameter
for this let’s just go ahead and put new flow layout right there and what this does is pretty
much give us our default layout so this adds a title and this gives us default layout so
now let’s go ahead and start building the actual item that we wanted to build so again
we already named item one so that’s item one equal to new jlabel and remember remember
labels are pretty much just text so this is how we put text on the screen and the argument
for it is what you want to help put on screen this is a sentence make sure you spell it
wrong and now we pretty much just have an item that says this is a sentence all we have
is text on the screen now now we can add some functionality to our item one thing we can
do is make a little scroll box pop up when you hover over it in that scroll box is actually
called a tool tip text so we can take that item one that we just built and set tool tip
text like that and now our argument is what’s going to appear when we hover over it so what
do we want to appear this is going to show up on hover or something like that so now
we built a line of text on the screen and now when you hover over it this thing is going
to pop up and we use that during the set tooltip text method little tongue twister and now
lastly the last thing we want to do is add the item to the window we made an item we
have a window but we didn’t add the item in the window so that’s easy all you have to
do is add item one so again don’t forget it just doesn’t automatically add it for you
have to actually add it why they did that I don’t know but that’s what they did so now
we have an item in pretty much our tuna class is done now go over to your main apples class
right here and we can go ahead and start building on the object for that or calling our toon
class so the first thing we’re going to need to do is import one thing right here import
Java X dot swing make sure it’s pillar right dot J frame and again like I said before this
pretty much gives you all the basic windows features so now let’s go ahead and start building
an object for tuna tuna I’m just going to name my object bucky equals new tuna or whatever
your class’s not going to take any arguments and now you need to do a couple things does
this object which is pretty much the window with a line of text in it what we want to
do is set and this is really important set default close operation right there and what
we need to put in here is how we want our program to close so put j-frame dot exit underscore
on underscore close all in capitals and what this does is whenever we hit the X button
the program terminates if you don’t have this then your program is going to be messed up
whenever you hit the X button is my screen recorder so we run all right just check it
now what we need to do is set eyes for that object or a window so again put Bucky set
sighs let me see how much time I got left two minutes so this is going to go real quick
Bucky set sighs and let’s just put it like 275 by 180 or something like that and now
the last thing we need to do is Bucky set set visible and I’m going to do this real
fast set true and this pretty much means so you can see it now let’s go ahead and run
this and what we got right here is this is a sentence and when you hover over it it says
this is going to show up on hover so again that’s what we built right here this is a
sentence put the title bar at the top and when you hover over it this is going to show
up on hover now I only have 30 seconds left so I can’t talk you through how we did this
all again but make sure you watch the next tutorial we’re going to be putting more stuff
in here and I’m going to be explaining how we did everything but again like I said I
don’t have time to do this tutorial because YouTube only lets you upload 10 minute videos
so um thank you guys for watching and I’ll see you next tutorial what is going on people
welcome to your 50 second java tutorial and the store is probably going to be pretty long
it’s probably going to be a multi-part tutorial and we’re going to be talking about event
handlers so what an event handler or event handling is is in Lesson toriel I showed you
guys how to build a simple GUI or GUI well what an event is is anything that the user
can do like move their mouse click a button press Enter those are called events in computer
language now what an event handler is is the code that responds to your mouse movement
or button clicking so the event would be click a button the event handler would be the code
that says ok when you click this I’m on another box the pop-up that says you just click the
button or something like that absolutely the event is what the user does the event handler
is what the programmer makes when they do that event and this overall process is called
event handling so I’ll be talking about this later on but you guys need to know um pretty
much I just want to tell you in this program or tutorial we’re going to be building a window
on the screen and we’re going to be building some text boxes inside that window and whatever
the user enters text and press Enter um the event handler is going to say alright I’m
going to pop up another box so let’s just go ahead and get started if you know I’m talking
about then you’ll figure it out eventually ok neat little break now the first thing we
need to do is import a bunch of crap that we’re going to use in this tutorial so I’m
going to go ahead and type import java.awt dot flow layout and make sure your egg is
not capitalized and go ahead and you can just copy this right here because we’re going to
be using something similar to it so we imported java.awt flow layout the next thing we want
to import java.awt events dot action listener let me make sure I spelled listener right
yep and what this does the flow layout pretty much gives you layout the listener listens
or pretty much waits for the user to do something like press ENTER or something so now the last
thing we needed poor import from the AWT is event come on cursor seriously AWT event action
event and these are events which I told you about last time now we need to import four
things from the swing so let’s go ahead and import Java X make sure you have the X swing
dot J frame and now we can go ahead and well might as well copy that because we’re going
to important three other things copy paste paste paste we need to import jframe jtextfield
and make sure that you got your cap elation same as mine with a TF capitalize jframe J
texture J password field in text field is somewhere working type text pest password
is the same thing but instead of showing the text it covers it up in Asterix so you can’t
see and the last thing is option pane so now we imported everything that we need for this
tutorial and these pretty much are all built-in methods and variables that we’re going to
use so now what we need to do for our tuna class is just like before we need to extend
or inherit all the stuff from J frame and what this pretty much does is give us all
it pretty much lets us to use a window so now we created a window like any other program
now we can start putting stuff in it so we’re going to put three items plus a password field
in it or pretty much for text fields so let’s go ahead and make variables for those let’s
make our item our first text field first so private J text field and you need to put jtextfield
and you can name anything you want I’m just going to name my item one and I’m going to
make three of these so I’m just going to copy this because I am extremely lazy item two
and I’m three in the lesson sorry about that head take a little break help my room I find
his phone but alright so we created three text fields right here now let’s go ahead
and create our last password field and we’ll set that to private as well because I mean
why not J password field like that and let’s just uh give this variable oops password field
looks good so now I did something oh no semicolon embarrassing so we created three items plus
a password field now let’s go ahead and create our window so let’s go ahead and create a
constructor for this and since of my class is named tuna I’m going to have to create
a method that’s named tuna so I’m just going ahead and go inside public tuna doesn’t take
any arguments and whatever I create in this is pretty much the window so the first thing
I need to do or first thing I actually want to do is add a title to this and if you remember
from the last tutorial to do this you just put super and then in your argument you put
the title or whatever you want for the title not going to get anything fancy because I’m
not creative at all so now we’re going to have to set the layout for this which is pretty
much how things are placed and we don’t want to have to code a new layout and place everything
so we’re just going to grab a 1 by default and how you do this put set layout and if
you’re wondering where all these methods are coming from they’re imported some are up here
all these built-in methods that I’m using you just can’t make set layout and put it
in everything you actually have to import it so set layout takes one argument and the
argument for this is new flow layout just like that and that is a method in itself so
make sure you have that up just like that so now we have a title in a layout to our
window so let’s go ahead and start adding those um textfields right there so the first
thing we’re going to add is the item one and we’re going to set this equal to nu J text
field and in the parameters for this set the length of it is 10 and now we have an item
but we didn’t add it to the window yet so let’s go ahead and add item 1 and this will
add the item to our window so now although you can’t say you pretty much have a blank
window with just a little text field on the screen now we’re going to go ahead and do
that for the rest of our items so let’s go ahead and put item 2 and set this one equal
to and these are going to be a little bit different just to change things up a little
bit new J text field but is your parameters go ahead for this one and put like enter text
here now what this is going to do is give you a default text inside and it pretty much
is like a prompt now let’s go ahead and add this one to the screen item 2 so now we have
a pretty much an empty window with two things on our screen two text fields so now let’s
go ahead and change our item 3 variable – yeah you guess the new J text field and for this
one we’ll go ahead and type all right let me think of something to do there we go let’s
go ahead and type we’ll make this text on editable and we’ll give it a default value
of 20 and now we have a text field that says uneditable in it and we want to make sure
that the user cannot edit this so we’re going to what we’re going to do is take that item
3 which is that text field and how you set the editable Ness is go set editable and what
you’re going to do for this is put false and if you put false in that that text field is
not going to be editable so the user is going to be able to change what’s on the screen
I mean I read what’s on the screen but they aren’t going to be able to edit it and now
what we want to do is just I’d add item number 3 to that and the last thing we’re going to
make is our password field just go ahead and our password field and we’re going to set
this equal to nu J to get it password field make sure it’s typed everything right and
as a default you can give um get out of there my pass or something and this is going to
show up in asterisks on your screen so now that we have that we can just go ahead and
add on the password field or don’t want that so now we have a screen with four things on
it we have four different text boxes and each of em them is a little different I just want
to show you guys that I’m changing the parameters does a little thing different to it and you’ll
see this later on visually but in the next tutorial we’re actually going to be adding
and event and handlers to this that means when you enter text and press Enter do this
or do that but for now I just wanted to get our window set up and in the next tutorial
we’re going to start programming this baby so I cannot wait thank you guys for watching
now see you next time what is going on guys welcome to your 53rd java tutorial and this
is pretty much a continuation of the 50 second one and there’s probably going to be a fifty
fourth one but i’m just a real quick view what we did pretty much already if you didn’t
watch 52 for some reason we just built a window and put four things in it and that’s a that’s
pretty much it and now what we’re going to do is pretty much add some functionality to
this and what we’re going to say is all right when you enter text and one of those text
fields and press Enter what we wanted to do is pop up another box saying what you entered
like when a user would type in something and it says like a verification or something so
let’s get right to it now what we need to do is the first thing that we’re going to
do is build an action listener object so what this means is we have four text fields waiting
on the screen and they’re pretty much dumb and they don’t do anything right now what
we want them to do is to add some brains to them and have them waiting on the screen in
listening it’s called and when you listen you’re pretty much just waiting for an event
to happen so right now they just look pretty they’re not even waiting for anything so what
we want to say is all right text boxes listen for something to happen and when that happens
we want you to execute a bunch of code so the first thing that we’re going to need to
do is we’re going to build another class to execute the code but this class I’m going
to build an object for this class before I even build the class so the class name is
going to be the handler and we’re going to get some errors right here but that’s fine
and I’m just going to name my object handler and this is going to be equals new handler
class and if you’re saying all right where is this handler class we didn’t build it yet
but I will we promise so actually hold on new the handler there we go and what this
does is it pretty much builds an action listener object so now we’re going to make a new class
later on arm that you’ll see what this does later but what we need to do is add this object
to each of the items so item one what we need to do is add action listener and what this
takes as an argument is the object we just created so that’s why we need to do that and
the object you can see it is called handler so handler right like that and we need to
do this for each object so let’s go ahead and copy this copy and paste paste I’m – I’m
three and of course our password which is password field right there and add add action
listener and this is of course going to take the handler argument again so now we have
an object of the class the handler which we didn’t make it but that’s what we’re going
to do right now so once you uh let me make sure here’s jframe here’s the one class here’s
where one class ends or pretty much our constructor and now here’s another thing I’m going to
tell you um this pretty much whole thing is our constructor which is pretty much a method
for um this tuna class and you probably think in our I’m going to build a new class I’m
going to build it on the outside of this well actually we’re going to build another class
but we’re going to build it inside this tuna class and when you do that when you build
a class inside the class the class that’s inside inherits all the crap from the class
that’s outside so that’s what we want to do so let’s go ahead and make this private because
it’s no need to make it public class and I hit insert class the handler or whatever you
named it right there and now we see we get a whole bunch of other error messages implements
P implements action listener and I spelled it there we go implements action listener
now what we want to do is go ahead and build body for this and now what we have is our
class and why did we need to name the handler because that’s what the object was and it
implements action listener and what this means is pretty much that this is going to be the
class to handle the events and you’ll see why later on but I know it’s confusing right
now but what this action listener class is is it takes one method there’s only one method
we’re going to be building in this class and that’s the method that’s going to be called
automatically whenever an event occurs and to do that type up lick void and I know this
doesn’t make any sense to you right now it’s weird because you kind of have to build the
whole program and see what’s going on but I promise by the end of this you’ll see what’s
going on action and you need to name this performed and as a argument you need to take
action event and then you need to name your variable something like event like that and
now as well let’s go ahead and start building the body for this so what happens in this
private class right here is as soon as an event occurs whatever happens inside here
is going to handle the event so let’s go ahead and type some stuff – um pretty much just
add a body to our method the first thing we’re going to do is build a string variable and
we’re just name is string and set it equal to an empty string and this is going to be
the final string the outputs but um you know we don’t need to worry about that now now
the next thing we’re going to want to do is make pretty much a huge if statement in you’ll
see why in a second the first condition we’re going to test if the event and remember this
is like an enter or a click and in this case is going to be if the event is going to be
when the Hugh can’t talk when the user presses enter so if the event equals get source and
the source pretty much means where it happens if it’s equal to item 1 and what this means
is pretty much if they clicked enter on text field number 1 then what do we want to do
well the first thing we’re going to want to do it is take that string variable that is
empty right now and we want to set it equal to string format and what we just use C style
formatting and we’re going to want to set this equal to put something like field 1 percent
s and put those in quotation marks so what this is going to output is field 1 with a
variable right here and as our variable what we want to do is press event and this is get
action command now this is the last thing in this tutorial that’s going to confuse it
what get action command means after I added my semicolon is get the text from that location
so if they type in Bucky and field 1 and press Enter what this is going to do is say alright
your event source or you hit enter at item number 1 so what am I going to do is put field
1 equals Bucky in you’ll see why later on but for now just follow with me the next thing
we’re going to do is build 3 else ifs so else if and just go ahead and copy this copy this
paste in event to field – and we’ll get the action command for that now let’s go ahead
and just copy this one more time copy make sure my cursor is in the right spot oh cool
it’s messing up cool I am paste if the vent get sorts equals from item three then we just
want output field three equals that and now what we want to do lastly is put else–if
and let’s go ahead and put event get source all right if this events occurs on what do
we name it password field then what do you want to do set the string while you mess it
up pause set the string equal to string format and and let’s just go ahead and do the same
thing the format is let’s put password field is percent s and arguments it takes is of
course event get actually in command right there so now make sure we’re good go don’t
have any errors decide from these and what error begin right here the method add action
there is undefined which is a worry about that later and the last thing we’re going
to want to do I actually am run out I’m so I’ll do in next tutorial in the next tour
we will finish everything up so thank you guys for watching I’ll see you then what is
up people welcome to your 54th and hopefully the last tutorial in this little three part
series and before I get started I just want to tell you guys about one error that I did
I spelled listener run like I always do and just change that to te NER in uh if you have
more than third grade education you should know that but I don’t so now we can go ahead
and continue with the rest of our tutorial so pretty much in this handling class or the
class that handles on the event what we did is we took a string variable and we set it
equal to an empty string or a string with nothing in it and then we say alright if they
type something in the box number one and press Enter then we’re going to say alright we’re
going to change that string to field one equals whatever you typed in if they did it in field2
field3 or the password field that’s what we’re going to do so now we all we pretty much did
is we changed that string variable so if they type Bucky for the string variable this pretty
much changes your string variable and now the last thing we need to do in this class
is pretty much output it on the screen somehow so this is the last line so don’t worry just
type the j option pane and why do we get to use this because we imported it up here at
J option pane and what this pretty much does is pretty much just a blank window and what
we’re going to do is show message dialog make sure I didn’t spell that wrong too and it’s
going to take two parameters the first parameter it takes is null don’t worry about that has
to do with positioning and the second one it takes is your variable you want output
in that string so now let me walk you guys through this one last time we imported a bunch
of stuff to use that’s not important the second thing we did is we pretty much built a window
I’m using J frame which we did in the last tutorial you should know what how we did that
now here just here we get to the good stuff what you definitely need in order to handle
events is a pretty much an event handling class that implements action listener and
we built that class right here now once we made that class we can create objects for
that class and we created a class or excuse me an object named handler so anytime that
you use this object it’s going to refer to this class right here and after we built this
class and we built this object we’re going to go ahead and add that object to each one
of these items now we gave each of these items some functionality so before they were just
sitting there and now once you press ENTER on them they actually do something and what
does has to do with this method right here now inside your class that handles events
you need this method and you need to call it action performed this is a built-in method
that has to do with the action listener class this method gets executed automatically whenever
an event occurs so the event has occurred is enter so whenever they press enter what’s
going to happen is it’s going to create an empty string it’s going to test what you’re
going to want to change that string to and then it’s going to output it right there so
this is all the hard stuff we did it right here so copy that and do exactly as I did
now that we made all the hard stuff we can go ahead and just execute it like we always
do so my main thing is called apples you can do anything you want the first thing we’re
going to need to import in the only thing so don’t worry import Java X Java X swing
jframe and this just make sure that we can use Windows in our main method right here
so now let’s go ahead and start calling our object so let’s go ahead and create a new
object called Bucky or whatever and my class was named tuna you can name it or whatever
a year you can name your object whatever you want but make sure well you should know how
to do this right now equals a new object from the class tuna and the second line we want
to put is the closed operation liquid before so we’re going to take that object which is
pretty much the thing we just created that window and set default there we go closed
operation didn’t it’s too lazy to type at all in the argument that this is going to
take solve this crap in my way is jframe da exit underscore on underscore closed and like
before this just means that whenever we hit X we want to exit the program why why they
don’t do automatically I don’t know but you need to do yourself the next thing we’re going
to want to do set the size of the window and we do this by setting the size and we’re just
going to set this to something like 350 mm by 100 like what the heck was that I just
had like a piece of skin in my mouth or something pretty disgusting by the way I got something
really disgusting to tell you um next tutorial or five time at the end of this tutorial but
it’s a disgusting story that I heard the other day so I’ll tell you then that last thing
we need to do is set the visibility so set visible and you learn how to spell so and
we’ll just set this to true and now let me walk you guys through this one last time so
now make sure you don’t have an errors anywhere and go ahead and click OK okay okay okay and
hopefully this works and now here is what we built go ahead and type Bucky press Enter
it says field 1 equals Bucky enter text here go ahead and type um Fred 3d field 2 equals
free D uneditable look this I’m typing I’m typing can’t edit it so go ahead and press
ENTER in that uneditable and this password on by default if you press ENTER it’s my pass
but you can go ahead and change it to like that and then it changes to gf GDS so I’m
going to tell you guys through this one last time how this works um if you don’t want to
listen to me you can go ahead and watch my next tutorial or watch some videos of like
dogs doing silly things online but for those of you guys who really want to figure out
how this works I’m going to tell you right now this is all well let’s go ahead and just
skip the good stuff right here in order to handle events in Java you need an event handling
class in that class needs to implement action listener and what action listener allows you
to do is put that listener on something which means all right I’m going to wait for an event
to happen and once it happens I’m going to do some code and that once we have this class
we can go ahead and create an object and why do we need to create an object well we need
to create an object because this add action or add action listener method it takes an
object as its argument so that’s why we needed to create an object and the object it takes
as the argument is how it wants to handle that event so why can’t it just automatically
know what event to handle because of this class right here well sometimes you have different
events in different classes so that’s why so now once we have this class that handles
the event and the object though we can go ahead and add some functionality to this so
what this method does is get performed automatically whenever you call this class it’s kind of
like a constructor but kind of not so and what this does is take the event is the argument
which is in this case the pressing of the enter button what this does is says alright
if event gets source which means where the thing occurred equals item one if it occurred
in text box item number one then what we’re going to do is set the string equal to whatever
was inside that text box if it occurred in item to set the string that was it what was
equal to in that text box if it occurred number three set the string equal to was in that
text box for the same thing and now once we set our string variable of something depending
on what was inside that text box we’re just going to output it in the J option pane which
was that little check box I mean that little box at the end that pretty much just said
Craig or Bucky or whatever I typed in there so that is your tutorial on how to handle
events I’m sorry is really long but it was also really necessary so I guys I hope you
understand pretty much the basics of what I did we’ll be going over this a little later
so if you don’t you probably figure it out but thank you guys for watching thank you
for supporting my channel and for all the awesome comments and some of the not so awesome
ones but again I thank all of you guys all the people who watch my videos so I can’t
wait to do next tutorial so I’ll see you then what is going on guys welcome to your 55th
java tutorial and in this story we’re going to be getting into polymorphism a little bit
and also talking about or building something called a polymorphic array to a demonstrate
why polymorphism is actually useful and it’s a pretty confusing topic and trust me they’re
going to be a lot of tutorials on this so if you’re not quite sure what’s going on by
the end of this tutorial then I promise you in a couple of tutorials you’ll be a pro on
polymorphism so in order to demonstrate polymorphism we first need to build a computer program
that uses inheritance in one way or another so what I did is I set up and you can probably
tell this if you watch my last tutorial I’m going to have a superclass called food in
this tuna class in Popeye class since they’re both types of food they’re going to inherit
all the methods and variables in this food class so the food is a superclass in the tuna
and Popeye or sub classes I already put extends food in what extends food does is using a
heritance to inherit everything for food but you should know that already if you all watch
my other tutorials just for the people who just started that’s what I’m doing so now
let’s go ahead and build a basic method called eat in food so void eat won’t take any parameters
and what it will do is pretty much go system print online pretty much system.out.print
line and it’s going to say take it there exists some out print line um this food is great
and now what tuna and Popeye does anytime you call the eat method it would say this
food is great now that’s nice and all but another thing about polymorphism and I’m just
going to do this for demonstration purposes we can over ate the eat method that if we
put it in the tuna class and called it it’ll say this tuna is great now and let’s just
do that one more time with Popeye this Popeye is great so even though it’s inheriting the
eat method from the food class we overwritten it or overrode it with putting a new eat method
inside the tuna and potpie class so now when you call the eat method in tuna it says this
tuna is great and now when you call the eat method in Popeye it says this potpie is great
so now let’s get into polymorphism now that we have a program that uses inheritance what
polymorphism is is pretty well first let me describe to you how we built on reference
variables and objects before we did something like tuna Bucky equals new tuna and we didn’t
really think about what we were doing we just did it because that’s how we were taught but
if you’re wondering ah right why do I need to put tuna right here and tuna right here
is well shouldn’t I only have to put it once to know that I’m talking about that class
well the thing is well first let me go over what these are this right here Bucky is the
reference variable that means whenever you refer to the variable Bucky you’re fairly
you are referring to controlling the stuff in this class or object which is tuna and
this pretty much is the data type so it can control the tuna data type and this object
is of type tuna but another cool thing is you can do this and this pretty much is the
intro to pot pull look look chicka-boom chicka-boom pond sorry this pretty much is the intro to
polymorphism not only is tuna of the tuna type but tuna is also of the food type so
what you can do is some pretty cool things anything that inherits from the super class
which is tuna or excuse me the super class is food can be assigned to Bucky for example
tuna since this inherits from food can be assigned to Bucky Popeye sense it inherits
from food can be assigned to Bucky interests A&R a that’s nice to know I can assign
this that and the other thing but why actually would this be useful in any kind of way well
the answer that I will do one thing which you guys probably need and that’s an example
the quickest example in the most clear thing I can do is build something called a polymorphic
array and this stores objects of different classes in pretty much the superclass type
so let’s go ahead and say we have food and that’s the type and let’s go ahead and make
an array object named Bucky and we’ll set this equal to new food to so now we have an
array and it’s called Bucky and it’s of the food type and remember like I said since we
have something of the food type it can hold objects of tuna and potpie so for example
Bucky zero can hold objects of new potpie just like that and we’ll set Bucky 1 which
is a reference variable and we’ll set this equal to the object of new tuna and you’re
saying all right well that’s still great you have one variable that can hold an object
and another very variable that can hold an object yeah these variables might be of the
food class but I don’t see why this is useful still well just wait a minute and trust me
you’ll see why in a little bit one reason for using polymorphism is to use polymorphic
arrays and that would be something like this you loop through this array and in essence
what it does is it calls each method of this class right here so let’s go ahead and type
for int x equals zero and just put something like X is less than 2 you can also put array
length but you know you don’t want to and do plus plus X and now what we can do is say
something like this Bucky X Y dot eat and what this is going to do is loop through each
one of these objects and call the eat method so it’s going to loop through the first object
which was assigned Bucky zero Popeye and it’s going to call Popeye dot eat which is say
this Popeye is great the next thing it’s going to do is loop through the tuna object which
is tuna D and then then it says this tuna is good so then you save yourself the trouble
of making a new object called tuna tuna object then you go tuna e and then you have to make
an object and you have to call each method and I just got rid of my curly brace right
there so what this pretty much does is loop through each of your objects and calls the
eat method for each one don’t believe me I’ll run it right here it says this Popeye is great
this tuna is great BAM how easy is that so that is pretty much your basics the polymorphic
polymorphic array you can assign different objects to variables as long as this reference
variable is of the superclass type in that way instead of having to build a new object
for each one of your you know having to build a new object every time you want to use a
method from that thing you can build one um reference variable of the superclass and assign
it to objects of the subclasses and just loop the room with a polymorphic array so how cool
is that and I know it’s really confusing at first but once I show you some other examples
aside from polymorphic arrays you’re going to understand exactly how to use this how
it works and you’ll be a pro at it so for now thank you guys for watching don’t forget
to subscribe and if you have any questions just leave me a comment and I’ll try to answer
them so thank you guys for watching again and I’ll see you next time what is going on
guys welcome to your 56th job tutorial and in this store I’m going to be talking about
more about polymorphism in how you can have polymorphic arguments and also return types
and bunch of boring stuff like that but I’ll try to make it a little exciting and maybe
I’ll tell a funny story maybe I won’t I guess you guys are going to have to wait and see
if you’ve been following my tutorials the first thing you probably noticed is I made
a new class called fatty and we’re going to we need to build this class to demonstrate
what fatty can do to food tuna and pot pie if you haven’t guessed he’s going to be eating
these classes because fatties love food tuna and Popeye trust me I know firsthand I fan
I love them so we made this fatty class now let’s go ahead and make a simple method in
here it’s going to do public void digest which pretty much means eat then but we can’t have
eat tuna because he is already method in here so we’re going to have digest and as a parameter
is going to take a food object so let’s go ahead and type food X and now we can go ahead
and do something with that object it’s tighten that up a bit that’s what she said so now
we’re going to pass in a food object and when we pass in the food object we’re going to
take that object which is now named X and we’re going to call the eat method to that
and bam that’s all all we’re going to do so here’s what we can do right now for example
if we had a food object named Bucky we can pass in the name Bucky and then it’s going
to say alright whenever we call Bucky II it’s going to say this food is great so when every
pass in the food object is going to call that food method which is eat right here but what
you didn’t know or maybe you did if you know Java what you didn’t know is anytime you can
pass in a food object you can also pass in objects of a subclass for example you can
pass in tuna and potpie so since this object or excuse me this method has the privilege
of accepting a food object is this argument it can also accept any subclasses such as
tuna and potpie so Oh would you say you don’t believe me well let me just go ahead and prove
it right here let’s go in our main apples method and let’s go ahead and start making
some objects let’s go ahead and make a fatty object and we’ll name it Bucky because that’s
me and I am fat we’ll say equals new fatty with no parameters so what we did here is
we created a fatty object named Bucky and let’s go ahead and now once we can use this
fatty class let’s go ahead and give us a way to use the food objects so let’s go ahead
and create food will create fo for food objects equals new food and why do we need to create
a food object because first of all put your semicolons get my wood box so he said and
I correct myself up sometimes and why did we need to create this object for food well
because this method takes an argument that’s a food object so that’s why so now head now
let’s go ahead and call this with our fatty object which is Bucky because I’m fatty we
put Bucky eat right there and now let’s go ahead and as our argument remember or excuse
me that’s digest isn’t it and as our argument for the digest method in our Bucky object
it takes one food object so we only have this object right here fo so let’s go ahead and
pass that in and see how it works okay run that baby and it says this food is great wow
that food must be great wonder what it is from a double cheeseburger you fat piece of
oh sorry and anyways now you pretty much know how you can pass in objects into methods but
wait Bucky you said that you can pass um subclasses in as well well I didn’t lie anytime you can
pass a food object in as a method as an argument you can also pass the subclasses which are
in this case tuna and potpie so for example we have this fatty digest method that takes
a food object is this argument but food also has the subclasses of Popeye and tuna so let’s
go ahead and make a food let’s limit P Oh equals new food get out here and BAM just
like that so not only can we pass in this superclass of food object we can also copy
this because we’re lazy and we can also pass in this object P Oh which would be the potpie
so let’s go ahead and run this and it will be new potpie like that let’s run it and see
what we got this food is great this potpie is great so what point am i exactly trying
to make well what we did right here is this we created an object named Bucky so we can
use all the stuff in this fatty class right here and the only thing is is this digest
method so you know I don’t have a whole lot to work with here we also created a new food
object because this digests method it took a food object as its argument now after that
we created a potpie object now this potpie object is a subclass of this food superclass
so any time this digest method can take a food argument it can also take a tuna or a
potpie argument as well so then I prove that to you guys because I know I’m a liar and
I had to prove it to you guys I called that Bucky object with digests is the food object
is my argument and I also called the Popeye object as my argument so that is pretty much
a way that you can have polymorphic arguments and you can also have polymorphic return types
in the same way so we just want over arguments right here but you guys can figure out just
return any other one if you want so that’s that for this tutorial hopefully you guys
learn if didn’t then you know I don’t know what else to do watch your ass my sorrows
I guess Oh disgusting story I told you guys that I’ll tell you one of my friends she went
to a well I don’t want to say the name of the restaurant but she went to a fast-food
restaurant before and she got this chicken sandwich and she bit into it it was like creamy
in the inside and she’s like oh cool like a new cheese on the inside must be like like
a cheese filling or something like that taste like blue cheese or something well anyways
she ended up getting food poisoning and they found out that in the center of the chicken
it wasn’t a filling it was actually pus in the centre of the chicken so when she bit
into it pus burst out and she thought it was filling and she just ate it anyways and yeah
she got food poisoning so if you think that’s disgusting leave me a comment and if you never
want to eat a chicken sandwich again then I don’t blame you but it wasn’t from McDonald’s
or Wendy so you guys are still good to eat there so in any way thanking you guys for
watching hopefully you enjoyed my discussing story in my tutorial so I look forward to
teaching you some more so I will see you next time oh by the way don’t please subscribe
what is going on people welcome to your 57th java tutorial and this tutorial is going to
be not a lot of coding actually it’s going to be pretty much clearing up a whole bunch
of concepts dealing with polymorphism and trust me you’re going to have a huge a better
understanding of polymorphism by the end of this tutorial so I just want to go over um
overriding a method or real quick in something I didn’t tell you about we built this superclass
called food in two subclasses called tuna and potpie we called a method and food and
we call to eat and we overrode that method in tuna and potpie each of these had a method
that overrode it so one thing I didn’t tell you about overriding a method anytime you
override a method you must take the same arguments as in the superclass method so since this
e argument didn’t have any arguments in it it doesn’t have like integer this tuna can
have like integer argument for this and this papaya can’t do the same whenever you put
an argument in here this is called overloading and that’s totally different but again if
the food if the main eat method doesn’t take any arguments which it doesn’t tuna and pop
pi can’t take any either and also in that same path it has to return the same thing
too so for example if you returned an integer in here it would have to excuse me if we return
an integer in the superclass it would have to return an integer in the subclass as well
and if you’re saying all right why do I have to do this why do I have to not take any arguments
and return the same stuff if I’m overriding it and in essence doing a whole nother method
well it’s so that you can have consistency and that is just so anytime you can call the
eat method in any of your other scripts then it pretty much guarantees that you can use
any of the sub classes as well so if all of these methods take the same arguments and
return the same things then they are pretty much interchangeable and that allows you to
use a subclass and substitution anywhere you can use a superclass so that pretty much then
you know what to expect and another thing I want to talk about anytime you override
a method so for example we have this food method in our superclass and we overrode it
with tuna we cannot change the scope of this so for example this food is public right here
we can’t put private void II see we’re getting an error already this changes the visibility
of it and why would you override it with a private anyway so you know you just don’t
want to do that and as I talked about overloaded method is not the same as override well overloaded
method is if you hear anybody talking about this an overloaded method is a method with
the same name but it has different arguments so for example we can do this in I and not
get an error but this is a whole nother complete method so then over so if someone calls eat
with a single argument then this method is called but for now I just want to tell you
guys that overloaded and overridden are two totally different things so don’t get them
confused so now that we got that out of the way in in essence I pretty much just want
to tell you that whenever you override a method you have to take the same arguments and same
return types there I said I just said it in like three minutes the other time so let’s
go back to our Fatih class right here and let me refresh your memories we know we can
do something like reference have a tuna reference and set tuna object equal to like new tuna
and as you know this is the tuna reference right here and this is the tuna object and
we can do this since tuna is a tuna and we can also do something like food food object
equals new tuna and we can do this because tuna is a food and those are the things we
learn in less orioles but what have we not seen so far what we haven’t seen so far is
food food object equals new food huh what about that well this is a problem for many
reasons tuna and Popeye we wouldn’t have a problem with and this is because when we put
variables in here like color shape tuna has a color tuna has a shape Popeye has a color
papaya has a shape food is too general it doesn’t really have a color it says what color
is food I don’t know what shape is food I don’t know and if you say alright I can eat
a tuna I can eat a pot pie but I can’t eat a food food is really too general and I know
that there might be some exceptions to this but for the sake of programming there are
some classes that are just too general that you don’t want to create objects on in this
food class is one example so if we had food class we want to want to give it any variables
like color or shape because food in general doesn’t really have a color or shape so all
right that’s nice and all I kind of knew that already Bucky so why are you telling me this
I mean I’m not giving you guys a tutorial to tell you guys that tuna has a color but
what I am giving you guys teaching you guys it says in even though we can’t create food
objects like right here we need this food class still for inheritance and polymorphism
but when we create this class we want to make sure other programmers can’t create food objects
either so how can we make this food class right here and and how can we kind of bulletproof
it to make sure that no one creates an object and they only use this class for inheritance
and polymorphism and stuff like that well luckily the cool people who invented Java
gave us this keyword and it’s called abstract and how you make a class abstract this type
a be STR a CT abstract right before the class and what this does is mean all right you can
use this class or right here the class of food but you can’t create any object sermon
oh yeah one bet look at this food food object equals new food object right there oh I did
oh look I got an error I guess bucket is right I can’t instantiate the type food and that
pretty much means you can’t create an object anymore so if we take that abstract away look
at this the air it goes away and now we can create an object so again what abstract means
is that you can’t create an object from that class but you can use that class from for
things such as inheritance and polymorphism and stuff like that and that is so when you
have a broad class that you only want to use for those kind of things then it kind of bulletproof
your programming and in the next tutorial we’re going to be going over the two different
types of classes abstract we went over in concrete I’m going to be showing you guys
an example of why it is useful and also what abstract methods are so this next couple tutorials
is more of general ideas and then we’re going to be building programs to use these ideas
and put them to use use them and put them to use did I say that right my good enough
but thank you guys for watching hopefully you guys understand that um anytime we override
a method you need to take the same arguments and also the beginning of what an abstract
method in excuse me extract class is so again thank you guys for watching please check out
my next tutorial and I will see you next time oh by the way don’t forget subscribe alright
guys welcome to your 58th jump tutorial and in this tutorial I’m going to be talking about
the two types of classes and in case you didn’t already know we already talked about the two
types of classes I just didn’t tell you the technical definitions of them now you guys
already know what abstract class is from the less toriel might as well put that back there
so an abstract class is a class that you can’t create objects from so it’s only useful for
polymorphism and inheritance and stuff like that in these other classes that aren’t abstract
even though they don’t have a name people call these classes concrete and the concrete
class is a class that’s specific enough where you can make an object’s or excuse me you
can make an object from it so even though it doesn’t say concrete that’s what people
call it just because they have to call it they just don’t want to be like not abstract
so again food you wouldn’t want to create something because it’s too broad a topic but
tuna and pie those are pretty specific aka concrete so you can create objects from concrete
classes but not abstract so again let me demonstrate this by saying all right whenever we try to
create a food object it’s too broad and abstract so it gets an error but if we go ahead and
create we can again we can have this food reference but if we create it from the class
like new tuna since this isn’t abstract we don’t get um well if I got rid of that then
we wouldn’t get an error right here because tuna has no restrictions we can create objects
from this now let’s get rid of this and move on to our next topic and so you know what
an abstract class is and it pretty much is useless unless you extend it or its inherited
from something and as you can see tuna inherits food and Popeye inherits fruit if nothing
inherited food it will be useless because you can’t create objects from it so that’s
what an abstract class is but just to make things more confusing I want to tell you that
it’s can be abstract – and what exactly is an abstract method well an abstract method
is a method that must be overridden so for example we created this method in food and
since tuna and Popeye inherited food we created a method eat in tuna and a method eat in pot
pie in both of these overwrote food I mean this wasn’t necessary that we created these
methods but we did it anyways just for fun so again an abstract method is a method that
must be over red in the sense it must be overwritten which means you need to create a body for
it then this body in the main food class right here this is unnecessary whenever you’re creating
an abstract method so let’s go ahead and create an abstract method right here let’s go ahead
and get it rid of everything in our food class how would we create an abstract method pretty
much the only thing you need to do is add the head in a semicolon so do public will
make it public abstract since it’s the abstract method void eat since it doesn’t return anything
and it’s named eat and now you can see this is a method but it doesn’t have a body and
if we’re saying alright i never created a method without a body well since tuna needs
to override it pretty much it needs to create a body for it and popeye needs to create a
body for it as well then that is why um in your declaration right here you don’t need
a body right here so again an abstract method in your superclass it doesn’t need a body
so another thing i want to point out anytime you have an abstract method and a superclass
that entire class needs to be labeled abstract – right there so you can’t have like an abstract
method and you can’t have this class be not abstract or else you’re going to get an error
like that so ever someone’s knocking on my door I think hold on oh I’ll let them keep
knocking I’ll get it after this tutorial and another thing I want to point out is when
we declared this public remember I said I can’t change the scope when we override it
so we need to make these public as well so make that public and if you see that little
error right here um multiple markers can’t reduce the visibility that is why anytime
you see an error with the word visibility you probably need to change public to private
or private to public or add one or the other so again like I was saying anytime you have
an abstract method you need to make the class abstract too but here’s the thing you can
have an abstract class but have abstract or non abstract methods inside it so again in
this is a we’re getting here because of something else here because anytime you have a non abstract
method you need a body but anyways I just wanted to point that out anytime you have
an abstract method you needs to be inside an abstract class but anytime you have a non
abstract method it can be inside an abstract class well you just heard it I don’t need
to repeat myself so the last thing I need to point out is let’s go ahead and make this
method abstract again just like this anytime you have an abstract method you need to implement
it in one or excuse me in any of the subclasses that extends the superclass now I know that
sounds confusing but listen to this all right this tune the class and this potpie class
both inherit from this main food class in this food class has an abstract method of
eat in it that means this tune class and this potpie subclass they both need to use the
eat method or or in other words they both need to implement or override this eat method
if you don’t have this eat method then you’re going to get an error in your class just like
this type pop I must implement the inherited abstract method food so again any time you
have an abstract method in a superclass then the subclasses need to override that method
and that’s like making a promise this food says all right you want to inherit from me
okay I’ll let you but I’m telling you I have this abstract method and if you inherit from
me you’re going to need to override it and Poppi’s like all right I promise I’ll override
it since you have an abstract method I promise if you let me inherit from you I will override
it for you so if like the classes could talk to each other that’s kind of the conversation
they would be having and for saying all right if I need to override this method anyways
what’s the point of even having it in here well it’s pretty much for consistency in some
polymorphism and I know that doesn’t make a lot of sense but in the next tutorial I’m
going to be building a program to demonstrate everything I went over in the last two tutorials
these last two tutorials were pretty much the rules and concepts that you have to follow
and I couldn’t just skip over it because it’s incredibly important for what we’re going
to be learning in that’s next up with tutorials and this is pretty much a core of polymorphism
these rules so in like five tutorials ago when I called a class or excuse me it was
an interface and I implemented it that’s what implemented means implement means pretty much
you need to override the abstract methods so that’s enough for this story I probably
should go see who’s knocking on my door but thank you guys for watching um don’t forget
to subscribe I got like phlegm bone up in my throat but anyways thank you guys for watching
don’t forget to subscribe and I’ll see you next tutorial what is going on guys welcome
to your 59th Jeff tutorial and if you’ve been watching last couple tutorials then we pretty
much learned all the really basic concepts of polymorphism and inheritance and stuff
like that so in this tutorial we’re going to be putting all our knowledge to use and
building a program that pretty much gets a class in puts objects in an array and it sounds
confusing but um you’re going to see what it is eventually but before I get into program
and I want to show you guys that I got rid of all my other classes because I’m going
to need a better example and I thought that this would clearly or better demonstrate so
I made a new dog class and I made a new class called fish in that I made a new class called
an animal and since dog is an animal and fish is an animal then I had them both extends
or inherit from the class animal and I didn’t want to do that just because it took time
but I pretty much made these classes and I have nothing inside them so if you want to
go ahead and do that you can follow along with me so then here’s a scenario we made
these three classes called dog fish and animal and our boss comes in in he’s like alright
Bucky I need you to program something for me I’m like what is he’s like I need you to
make a new class called mmm well name it dog list or something like that and in this class
I want you to have an array that we can add dog objects so like I said an array can hold
many things again hold numbers again hold strings it can also hold objects and this
comes into use um well we’re going to be finding out why a little later but in this tutorial
we’re going to be building a new class in a new array to hold dog objects why because
our boss told us to so let’s go ahead and do it the first thing I want you to do is
go ahead and under package under your source right click it and click a new class I know
you probably can see it so I will move it down source new Wow now you really can’t see
it but anyways if you click a new and class you get this thing that pops up and just go
ahead and put dog list or something like that and now let me move this back so there we
go now we have let’s see one two three four five classes and we have this new dog list
class and in this class we’re going to be building an array to hold objects from this
dog class and the fact that extends animal is irrelevant for now so we have this dog
list class and our boss wants us to build an array so let’s go ahead and do that first
let’s go ahead and make a private because no need to make public dog and we’re putting
dog and we’ll name the array the list and we’ll set this equal to new dog with parameter
of five or an array length of five and we put this dog and dog even though we named
the array the list we put dog and dog right here because that is what objects it’s going
to be holding it’s going to be holding stuff from the dog class so now that we have an
array named main list let’s go ahead and the only other thing we’re going to need to work
with our Ray is a counting variable so let’s go ahead and name private eye equal zero you
can set equal to X if you feel more comfortable with that boat what’s this error saying right
here all right we need an int private int I equals zero so now we have an integer that’s
just a counting variable that’s going to help us work with our array so now let’s go ahead
and build a new method to add dog objects so again or not again we need a method named
public void we’ll name it add you can name here’s what everyone I’m just going to Emma
add because it makes sense and as a parameter whenever recall this it’s going to take a
dog object and we’ll name it D for now short and sweet and the first thing we want to do
in this method is do a if statement so let’s go ahead and make if and we’ll put I which
is our counting variable that 0 now is less than the list dot length and what this pretty
much does is check if your array is fuller or not so if I the counting variable is greater
than five then your arrays already full so it would just I mean the method to run but
it wouldn’t add another one to array because this can only take five elements so four seven
and we try to add one then it wouldn’t do anything so if it is less than length which
means if it still has room in our array what do you want to do well the first thing that
we want to do is put the list and I which would be 0 now we want to set it equal to
D so we’re pretty much just going to loop through the array and every time we call this
method add an object to that array element then just give us a little um system.out.print
line on screen something that says like dog added at index space and we’ll pie right there
come on come on there we go and we’ll just let’s go to right now so now we have just
a little something on our screen that we can see visually because you know we want some
feedback here so next we’ll just increment through I so here’s what this method is doing
it pretty much checks if your rate is full or not if not it adds that object at that
index and then it says just gives us the little message on the screen and then it goes to
the next counter so we don’t keep adding it in the same index in our array so now we built
this class just like our boss said that has an array name the list and it’s going to loop
through every time you call this method it’s going to add a new object to the array so
let’s go ahead and do this in our own main method I named mine apples I don’t know why
but I did so now let’s go ahead and make a dog list object so let’s go ahead and put
dog list I’m going to need my diello you can name your object anything you want and then
just put equals new dog list so you should look the exact same as mine except if you
didn’t want to name it diello you don’t got a so now we can go ahead and create a dog
object because I mean we need one as our parameter so we create dog D or if you don’t have a
dog class then whatever you have and we’ll set it equal to new dog object just like that
doesn’t take any parameters because it doesn’t even have any constructors or anything now
what we have to do is pretty much call the method in our dog list so use that object
diello whoa embarrassing diello that’s our method type it and we have a method called
add in there remember that’s what our method was called and it takes a parameter of an
object a dog object and we have a dog object right here dog D so let’s go ahead and put
D as our parameter right there and that’s it pretty much just to run this baby click
OK and now if everything goes right it’s just say dog added at index zero and if we added
another one I would say dog added it index 1 and we’ll go 2 3 4 and it will go all the
way and that is because we set this equal to a length of 5 which means index 0 1 2 3
and 4 so that’s your real basic tutorial on our how to create an array to add objects
into it but then what if our boss comes in and says yeah come in boss hey Bucky I got
a little problem what’s that boss alright you know how I told you create a dog list
to hold dog elements or excuse me dog objects well now on the people were working for they
said all right I want it to hold fish elements too so how are we going to fix this problem
well that is a problem for the next tutorial and that’s what we’re going to be doing and
trust me you don’t just add another entire class called fish what we’re going to do is
making this bigger and better and you know it’s just going to be awesome and you’re going
to learn a lot in next tutorial so thank you guys for watching and another thing um my
500th video that I add I have like 491 my 500th video is going be the best video in
the biggest surprise for you guys ever so you do not want to miss this 500 video it’s
probably being released this weekend but is going to be incredibly awesome and trust me
you guys are definitely going to want to see it so for now thank you guys for watching
don’t forget to subscribe and I’ll see you next door what is going on guys welcome to
my 60th job tutorial and in the last tutorial we went ahead and we built a new array and
in essence we built a whole new class to create this array to hold dog objects but then it
ended tutorial got a little knock on our door and our boss was like alright you know how
you created that for dogs well actually I need you to create one for fish as well and
you know that’s nice and also what can we do what are our options we can go ahead and
create a new fish list and do this all again or you know then we’re going to have if he
comes back again and tells us to do it with dolphins or cats we’re going to have to keep
doing that again and again and again so instead of just having to create class after class
after class I wish there was way where we can only create one class and it could hold
fish objects and dog objects and any kind of animal that we want so then when our boss
says alright I need you to actually create one to hold um Birds we’re going to make oh
you know what already done because we already built a sufficient and effective program to
hold all classes of animals even the ones that we didn’t even know um that were created
yet so how would we do that well this dog list is nice but let’s go ahead and delete
that right now delete and okay so instead of just creating a bunch of different classes
to hold objects let’s go ahead and make one final thing and we’re going to name an animal
list so let’s go ahead and we can delete everything out of our main apples or whatever your main
our method is and now let me get rid of that error and now let’s go ahead and create a
new class by right-clicking source new class and one go ahead and name this animal list
and this is going to be um pretty much let me run this so X is annoying me there we go
and this is pretty much going to be on the class that has our array too or any type of
animal whether it be dog fish if you decide to create a dolphin class later if you die
decide to create a hermit class later it’s going to already on be able to hold that so
the first thing that we’re going to want to do is create an array to hold type animals
and remember these dog fish since they in sixth end animals all of these are type animals
already so let’s go ahead and put private um animal I didn’t yep animal and we’ll just
name it list equals new animal five so what this pretty much means is recreated array
an array name the list and it can hold five objects of type animal right there so after
let’s just go ahead and make our counting variable perhaps I equals zero and now we
can go ahead and build I always do that int I equals zero and now we can go ahead and
build our method and that’s public void void we’ll name it add still but we have to spell
void or right add and we’ll put animal a so now it takes one parameter which is an animal
object and now we’ll just do that test again if what do we name it the list or actually
we want to do if I is less than the length if I is less than the list dot length so it
would be five in this case but just in case you change this then you won’t have to change
it each time so that’s why I’m doing that so if I is less than the list length what
do you want to do let’s go ahead and do exact same thing we did last time the list the index
for that which would be I so at first one I would assign the list zero set it equal
to a which is the animal object next let’s just give us a little prompt on the screen
like system.out.print line and we’ll just have mo added at index space plus I so this
pretty much just gives you a little message on the screen and the last thing we want to
do is increment I because if we don’t it’s just going to keep adding to that same index
over and over again so each time this runs it’s going to change that counter variable
that allows us to move to the next element in our array so now that we got this animal
list it’s going to take any animal object we have and let’s go ahead and I’ll show you
guys that right now so in your main class whatever you named it I named mine apples
still don’t know why we can go ahead and create an animal list object from this animal list
we just created so let’s go ahead and put animal list alo you can name it whatever you
want new animal list BAM just like that now let’s go go ahead and create a new dog object
because remember that method takes a an animal object as its parameter so go ahead and actually
you know what I’ll do I’ll create a new dog object and a new fish object so dog will just
name it D because it short and sweet with a new dog just like that going to put fish
from our fish class create an object from here F equals new fish like that now we can
go ahead and call the add method in our alo add first of all we’ll add that dog and I
will do a ello add and now we’ll add that fish object so now if we go ahead and run
this you can see our a animal added at index one this is the dog object an animal added
or excuse me animal Atta in the zero this is the dog object an animal added in next
one that’s the fish object right there so again what we did real quick overview we created
an object so we can use the methods from this animal this class we created two objects of
dog and fish which were both animal type and we go ahead and we just called the add method
so it first added that dog element to index 0 and add the element to index 1 and we can
call that five times and then that’s it then our array is full if we call it after that
then it’s just gonna it’s going to run the program but it’s not going to add it to our
array because it’s already full so this is a much smarter array than we built last time
because now if someone wants to create a new class that was like hermit crab like I said
before all they need to do is put extends animal and it’s automatically an animal type
so that way we don’t have to create a new array for dog fish hermit crab dolphin gopher
watch out beavers we just needed to create this one class right here and it took care
of all those problems so if you think this array is pretty smart just wait to the next
tutorial we’re going to build this computer program even smarter and better than this
and if you didn’t think that is possible then trust me just wait to my next tutorial and
one other thing and I know you heard me before if you watched my last tutorial my 500th video
is going to be amazing and it’s going to benefit no one but you guys so um a couple you people
might already know what that means what I’m hinting at but trust me it’s going to be the
best video for you guys ever so thank you guys for watching don’t forget to subscribe
and I will see you next tutorial what’s up guys welcome to your 41st jump to
tutorial and in this story as promised I’m going to be building a four different objects
and these objects are going to use this tuning class and depending on how much information
they have them they’re going to use a different constructor for each one so let’s go ahead
and do that right now so let’s get some spacing right there so you can see it good adjust
my headphone and bam I’m good to go so in order to make objects let’s go ahead and name
this tuna object and we’ll set this one equal to new tuna and this isn’t going to take any
arguments at all so if we go look in our tuna class right here and you know that it has
no arguments because nothing’s in here we look at which one of these constructors has
no arguments well this one has our this one has a hour in a minute that’s two numbers
this one has three numbers but this one right here has no arguments right here so what it’s
going to do is insert three arguments and call this constructor again so then it’s going
to go down here where this one takes zero zero zero it’s going to set the time to zero
zero zero and then set the hour to zero in meant to zero and seconds to zero so now that
we have that let’s go ahead and build some more objects but this time let’s give them
different parameters or different arguments so let’s go ahead and copy this and paste
paste paste and one name is tune object two three and four and we’ll give this one to
an object two we’ll give it one parameter we’ll give it an hour of five we’ll give to
an object three two parameters we’ll give that an hour five and a minute of 13 and we’ll
give to an object for an hour of five minute 13 and seconds of like 43 or something so
for example this one right here it has two arguments so it’s going to look at this constructor
right here is this constructor good for me no this has zero arguments and I got two so
I’m not using you what about can the this constructor good for me well I got two numbers
and this one only lets me insert one so I ain’t using you what about this one well this
has three and I only got two so I don’t think so oh man the last one’s just right I got
to you got to let’s use a baby so that pretty much what happens with these objects that’s
what’s going on right now but now that we got these objects let’s go ahead and actually
use them and so let’s just go ahead and print out the time so system.out.print f we’ll just
do a simple print format and again this takes two arguments the first argument is how you
want to format it and I want to format it and since we’re going to be using on this
right here public string to military this returns a string so we probably want to put
a percent string with a new line right there and actually new line goes this way I believe
that would have been embarrassing and so this one returns a string so now we can use our
tuna object and then put something like two military with no arguments and what this is
going to do is is going to return our tuna object with no arguments right here so let’s
go ahead and your might as well do the other ones right now while we got this nice and
copied this is tuna object two three and four now let me run this and make sure I don’t
have any errors and hopefully it runs right and bam look at this now the first one was
object it was just tuna object and we didn’t enter any parameters the second one we entered
a five for the hour and it filled in zero for the rest the second one we entered a five
for hour and 13 per minute and it filled in the rest of the zero and this last one tuna
object for it filled in all of them for us or actually we did ourselves so let me see
if I can position this row since my screen recorders messing up again and now let me
go through one of these and show you guys exactly what it does not dud by the heck did
I say that so anyways let’s just pick one that you can understand easy and how about
tune object 3 right here we made an object that had two parameters right here five and
13 so went to tuna where it creates everything and it went to our constructors and it says
alright which one of these constructors has two arguments this one has two arguments right
here so I’m going to use this one this one has 0 1 and 3 so I’m going to use this one
that has two well what it did was plugged in what was our numbers 5 and 13 they used
the 5 for our the 13 per minute and they used the default of 0 and it called this constructor
again but this time it used its 3 new numbers so whenever you use the 3 numbers it it uses
this constructor right here and what this constructor does is set time it caused the
set time method so now it says all right I’m going to send you to the set time method so
let’s scroll down and see what the set time method tells us to do well it tells us to
do three more methods right here set our was pretty much checking those between 0 and 24
which it was it was 15 I mean 5 set minute check to between 0 and 60 which it was and
set second that was that zero plugged in for us arm that we didn’t have to do anything
for that so then we said alright we’re good there so then when we finally called on the
two military method what did it do well would pretty much just said our a we want to use
this method for that object right here so what we’re going to do is get that hour which
was 5 get that minute which was 13 get that second which was 0 by default and I’m just
going to return them all to you and a nice pretty looking string format right here so
that is why whenever we called this to military it just outputted the drink right down here
5:13 zero so that is of course a very complicated way but again you need to know it on how you
can use overloaded constructors to let me scroll down here to make a bunch of different
instructors based on how much information you enter and in that example I just told
you since we enter two I pick this constructor and that is how you can pretty much use different
objects with different amounts of information in it so um this will be clear when would
be when pretty much we’re building more programs and this was just an example so it might be
a little fuzzy right now but you’ll understand eventually in the next couple tutorials so
thank you guys for watching hopefully you understand at least the basics of overloaded
constructors and how they are useful when creating objects with different argument links
so again thank you guys for watching don’t forget subscribe to my channel and I will
see you next tutorial what’s up people welcome to your 42nd java tutorial and in this tutorial
I’m going to be going over a built-in method that Java has it’s called the two string method
and I’m going to show you guys what it is and why it’s useful and we’re also going to
be building part of a bigger program on this prep it going to be a two-part tutorial so
um pay attention and it’s going to be sweet so the first thing that we’re going to need
to do is get three variables and they’re all going to be private and they’re going to be
month day and year so private int month and just go ahead and copy and paste that take
advantage of our laziness 12e control V int day and private int year so now we have three
variables right there so let’s go ahead and do something with them the first thing that
we’re going to want to do is build this pop pie again you can see my pot pie class so
I’m going to build the pot pie constructor so go ahead public and just go pop pie and
it’s going to take three arguments it’s going to take int m per month in 2d for day and
Y for year again you can name these anything you want not important but remember to set
your variables which were your private variables like month equal to whatever you are corresponding
letter I just put MD and y for obvious reasons so that private date variable is going to
be set to whatever we pass in for D and that private Y is going to be set to whatever we
passed in for Y so now we got our constructor but we want our constructor to do one more
thing we want it to print out a string so and we just want it to print out so it can
know so we can know that our constructor worked or didn’t work make sure you put an equal
sign right there so let’s go ahead and system.out.print F we can just print format and I already started
filling them in for us so let’s go ahead and print out a string so let’s put um Quan house
but the director make sure we spell it wrong for this is and then we’ll go ahead and put
percent s and that means string and then go ahead and put a new line if you feel like
it if you don’t feel like it you know you don’t got it and now as you can see right
here our C style format it takes one string argument so in our second argument just go
ahead and write this and when we write this what it means is this the key word this what’s
highlighted right now this is just a reference to whatever object we just built whenever
we call this class so it’s going to say alright then what the heck do you want me to put for
a string well that’s what we’re going to be going over in this tutorial right now anytime
that you need a string representation of an object Java built this thing called a two
string method so let’s go ahead and write public and we’re going to be building that
right now public string to string and I know month is most of the time you can call your
methods anything you want but you can’t you have to say to string in this case and go
ahead and it takes MC parameters and in your body of your method go ahead and return whatever
format you want so return string format and then go ahead and % go ahead and % WTF does
that mean go ahead and put this um I mean you can write in whatever format you want
but just follow on percent d % d % d that’s the common date format and that has the month
day and year so the month / day / year / so this is what this is going to do well let’s
go ahead and finish our tutorial and then you can probably see what it’s going to do
then I’ll talk you through it one more time what we need to do is go ahead and create
an object now and I’ll call it pop pie and I’ll just call it like something like pots
object that pop object is not important and then whatever new pop pie and I know I should
have like proper months and days and years but I should have four or five six six seems
like a good year a long time ago so now that we go ahead and create this object we should
get a nice little string at the end if I didn’t mess anything up and it says the constructor
for this is four five six so now let me take you guys through exactly what I did what I
did is create an object using the parameters four five six so let’s go ahead and look what
happened when I created that object it said alright since the first thing I’m going to
do is this constructor I’m going to pass the parameters four five and six and four month
was equal to four day was equal to five in year was equal to six what the constructor
also did is say alright every time I create an object I want you to print out this string
but we had in the string variable instead of an actual string we had a reference to
an object and anytime you reference an object and it needs something in the string format
it looks to this method right here what this method says is anytime you need a string representation
of this object you look to me I’m two string I’m built in Java that’s what I’m for so that’s
why it outputted this right here the constructor for this is four or five six this is where
that format four or five six comes from right here and in the next tutorial if this seems
kind of confusing I’ll show you guys a useful way why to string is actually used and not
only you know it might be a little confusing to understand I mean this is just an example
it doesn’t really anything but in the next tutorial I show you guys I’m like one example
where we would actually need it and use it but for now hopefully you get the main idea
again the key points is the probably two things you’re going to be confused upon is this I
mean what’s highlighted right now any time you use that key word this it’s a reference
to the current object so it’s going to say all right just reference the curring up the
current object so it implies that it needs a string so since it needs a string it says
all right I need a string here says oh I see that’s why you gave me this two string method
so anytime I need a string I know where to look so makes sense and if it doesn’t it will
in next tutorial but for now thank you guys for watching hopefully understand the basics
of a two string method and don’t forget to name it two string that’s very important so
again thank you guys for watching and I’ll see you next door what’s up guys welcome to
your 43rd java tutorial and in this tutorial we’re going to be building the rest of our
program and I’m going to be teaching you guys about something called composition now what
composition means is that it means that a class and this is the one we’re going to be
building today instead of just the variables and methods it can also have references to
other objects for other classes and it could uh well I’ll show you guys what it means so
go ahead in our toon class again in the last story we built this Popeye class in our tuna
class just clear everything out and we’re going to have two um members for now go ahead
and type private string and this is a new one name and that’s going to be used just
to store my name or something and we’re going to also have a reference to another class
the potpie class so go ahead and type private potpie and type birthday since this program
is just going to output my name and the birthday but it’s going to do in cool way so now that
we have two members of this class right here we have a new name variable and we have a
reference to a Popeye object or object so let’s go ahead and well let’s use it so the
first thing we want to do is build our constructor so this class is named tuna so we have to
name our method tuna and that’s constructor what this constructor is going to take is
two arguments it’s going to first take that string variable that we have and we’ll just
name it the name so we don’t forget and we also want a reference to our pot pie date
object so let’s go ahead and put pot pie and let’s go ahead and write the date or you can
write the birthday or something like that and now in the body of our constructor let’s
just go ahead and set name set equal to the name and this go ahead and set birthday that
we declare it up here and set it equal to the dates so now we are in sync we are good
to go but what we wanted to do now is go ahead and make another two string method so let’s
go ahead and put public string to string and just like we did in the potpie class and this
method it’s going to take no arguments and for the body we want to return a string of
course so string format in for our format I really like when it fills it in for you
you know I want to do the work myself and in our format just go pull my name it is % s
and that’s going to fill in your name and then let’s go ahead and put my birthday is
percent s and here’s work is kind of tricky name birthday so now if you guys can understand
the next thing I’m about to say you’ll understand um the next thing I’m about to say sounds
easy enough but you understand the key concept of this tutorial so now whenever we call whenever
we need a string representation of this what we’re going to do is this it’s going to return
my name is and it’s going to look right here to see what it wants to fill in for name well
the name was up here and it’s going to be whatever we gave it passed it in but for birthday
there isn’t a really string name birthday birthday is just a reference to the date object
and again what this means since it’s a reference to an object and not a string any time it
needs a string from an object it’s going to say alright anytime you need a string and
I’m only object I’m not a string maybe I can help you out well I’ll go to my class and
I’ll go two two string method and then I can give you the information that you need so
when I put percent s right here you don’t necessarily need to pass in a string object
or excuse me a string variable what you can do is pass in an object instead and whenever
it looks in that class it implies through via the two string method that this is the
string you’re looking for so again you can do two things when you’re using this you can
either pass in a regular string which is just like a bunch of letters or you can pass in
an object and whenever you do pass in an object it looks into that class and it looks to the
two string method of that class so that’s two different ways when you’re using the print
format that you can do that so now that we got a two string method which is pretty much
the string representation of an object in the tuna class and we got a string representation
of an object in the potpie class I think we’re ready to build some actual objects now put
them to use so go over in your main Bucky or I don’t know whatever you named it and
let’s go ahead and build some more objects one more to be exact so now that we already
build one from Popeye we probably don’t even need that anymore but we’ll keep it up for
good looks what we want to do is build one for tuna so tuna tuna ooh got the hiccups
tuna object make sure I typed everything or I got the hiccup in between there and new
tuna and now we need to pass in two variables again this is going to take two parameters
because look our constructor takes two parameters it takes a name and it takes an object so
for the name let’s go ahead and pass in Greg and for the object let’s go ahead and pass
an object that we just built right here so in order to see what parameters it takes look
in your tuna constructor and you can see it takes a string and it takes an object well
our string is Greg that’s my real name and our object is pot object and we just build
it up here now everyone knows my real name oh great so now let’s go ahead and just output
what we did so system.out.print line and let’s go ahead and just write una
object but we have to spell array and we better change that to Bucky for good looks and now
oh let’s see it should be good to go so let me run this see how many errors I got and
then I’ll talk you through one last time what we did it says my name is Bucky birthday four
or five six you got it so in the first line in line number three we built a constructor
in the second line we built a tuna object well I guess we built objects and both lines
but here’s what that you already you guys already know this one did from last toriel
and for the tuna object when we build it in the constructor we passed in two arguments
my name in this object right here it took the name and set it equal to name and it took
the object and set it equal to birthday and then it says re just return it in a string
format well my name is Bucky easy enough my birthday is this object and it says all right
how am I going to turn an object into a string well anytime I want to turn an object into
a string I just go to that class and go to the two string method so again I’m going to
repeat at any time you want to turn an object in the string it looks to that class in the
two string method so that is your quick tutorial on what the two string method is and also
again like I said this is called composition and that’s referring to objects I’m going
to show you guys that’s referring to objects in other classes as members so this was composition
right here so thank you guys for watching let’s see how much time I got oh just in time
so thank you guys for watching make sure to check out my next tutorial get out of my white
house and make sure subscribe my channel because you know especially I’m lever so I’ll see
you later sup guys Bucky welcome to your 44th Jeff tutorial and in this tutorial I’m going
to be going over something called enumerations or enum we learned about them before I think
we might not have if we didn’t you know no big deal we’re both learning today but the
first thing that we’re going to do well let me tell you what enumerations are they’re
pretty much kind of like classes but they you’re going to use them to declare constants
at least in this tutorial you are so let’s go ahead and anytime you want to do this instead
of public class tuna you put public enum DNA um and now you can use this in a specific
way so like I said the first thing we’re going to want to do is declare a bunch of constants
of the enum type so let’s go ahead and make some constants or these are pretty much going
to be like variables that never change so I’m going to make like three names Bucky and
these are in essence objects so let me give these a few parameters and then you’ll see
why later on Bucky let’s give the first parameter a description word of the object and I’m going
to put nice since you know I’m doing this story might as well say something good about
myself and then let’s just go ahead and put a string about like um how old they are or
something I’ll make it interesting for the other two ones now let’s think of a next person
let’s think of a will do constants of my first girlfriends so my first one was Kelsey and
she was she was cutie it was fifth-grade she’s pretty cute and uh let’s see when I went out
with her I was ten years old and now put a comma because we’re not done with our entire
enumeration list and then the next girl went out with was oh it wasn’t really girlfriend
but uh we had thing it was Julia she was a she was a big mistake and I was twelve years
old when I went out with her so now we’re done we got three constants let’s go ahead
and end the statement with a semicolon now what we’re going to do is since we just made
objects and again each constant is an object and it’s going to have its own set of variables
in this entire enumeration so let’s go ahead and give it two variables that we’re going
to use later drive it final since we don’t want to change string since this we’ve just
made since we’re in quotation marks and put DSC for description and we’ll copy this entire
thing copy paste and we have description right here and what’s good name for this year or
something year so now we have three objects which are actually enumerations or column
or constants and they each have a set of their own variables one for description one for
year so now what can we do what do we usually want to do when we create these well the first
thing that we’re going to want to do is create an enumeration constructor so let’s go ahead
and do that by of course typing the name of your class and then you probably want to play
your two variables and put string description and make sure since this is um we’re going
to use this make sure this is different than this and you should know why and then just
put string and let’s put birthday or something it isn’t their birthday but I don’t want to
get confused at all I can’t put yr something because they’ll just confuse me you know I’m
easily confused got something to say about didn’t think so so now let’s put DSC or whatever
you declare it up here just put equal do description statement and then go ahead and put birthday
year evil birthday and now what do we got anytime here’s what’s going to happen with
Bucky is going to say all right with the object Bucky give it two variables a description
in a year for the description pass in nice in this 22 we’re going to see his birthday
so set your equal to birthday so now we can work with DSC in year good enough but now
that we have a constructor we just pretty much set these variables equal to where they
need to be we have no way of getting the variables yet so let’s go ahead and create two methods
that we can get the variables so public string so this is going to return a string and put
get description or get deaths if you’re lazy which I am so it works out and then in this
one we want to return the des see that’s just going to return a string of the description
easy enough and guess where we’re going to do in this method public string get output
get year seems like a good name and this one is just going to return year loan from of
this it’s a little too easy so now this is all we need to do with enumerations again
enumerations are constants that are also objects pretty much and so we needed two variables
to represent the two arguments and then once we have those two variables we can build a
constructor and then this constructor allows us pretty much to set these variables equal
to each other and return the information we wanted so let’s go ahead and well let’s just
go ahead and use the information right now so what we want to do pretty much in our main
class right here with our main method is build and enhance the for loop so let’s go do that
right here for and the first parameter you need is of course the class name in the variable
that you want to use in your for loop like we use um like description right here this
is just variable that we just made up this is going to be the variable that we just made
up right here and that’s the first like it’s pretty much what you want to call your objects
when you loop through them the next argument is you need an array that you need to loop
through and tell you a little bit about this because this might be kind of confusing anytime
you make an enumeration like this Java automatically makes it takes this constant these constants
and makes a built-in array and the array is called whatever your enumeration is called
instance on a my toon it’s called tuna and when you write values like that this is a
built-in an array of the constants right here so for saying are a um I need an array BAM
you got an array right there and again you can’t change this keyword values this values
is called a static method in again this is how you get a built-in RA so this is going
to loop through each of the constants first it’s going to loop through Bucky and Kelsey
then Julia and it’s going to assign them to people well you’ll see what does so now we
just need to make a print statement so let’s go ahead and put system and why do we need
to make a print statement so we can actually see what’s going on system.out.print out and
let’s just go ahead and make our two arguments the format is going to be percent s and let’s
put a tab add some spacing % s @ @ ab % s and a newline so it’s going to write our name
our description our age and then it’s going to go to the next person so now we need our
arguments the first thing we want is people because that’s what the object is pretty much
so in the first one is just going to loop through our name which is this Bucky in our
next argument what we need is to take that people object and use the method get’ why
would I name that method people dot get description and what that is going to do is it’s going
to return a arm you find my screen recorder see how much time I’m at I got minute 30 what’s
going to do is return a string of our description and this last one people dot get year and
what this is going to do is first find you to get it messed it up for me people to get
ear and what this is going to do is return a string of the year so let’s go ahead and
make sure I have a semicolon at the end of that and once again and make sure I have this
and let’s go ahead and run it so run this okay and look at my results I got the object
the description and the year object description your object scription yer so what it did again
see if I can get it was it loop through the entire array of people and for the first argument
gave us the object name description name and the year whatever year I signed will so in
the next tutorial we’re going to be going over this more but thank you for watching
don’t forget to subscribe and I will see you next tutorial so people welcome to your 45th
draft tutorial and in this story I’m going to show you guys how to get a range of constants
now this is going to be about eight times easier than the last tutorial so you know
just suck it up pay attention and I try to make it interesting for you so essentially
we need a range of constants and we only have three right here it’s not going to be very
exciting first of all and what kind of range can we give a three so let’s add a couple
more of my ex-girlfriends to list I had one girlfriend named Nicole and let’s find a description
word for her she was Italian and I dated her when I was I know probably like 13 so I’m
going to put 13 and don’t want that semicolon and my next girlfriend after this I would
have to say is candy this is when I moved to my new school she was my first girlfriend
and let’s say she was um let’s put this nice she was different and um let’s see how I was
in eighth grade so what’s that 14 maybe I’m wrong but you know we don’t have time to think
we just have time to do and let’s see after candy go in ninth grade but you know what’s
the fun in that there’s this girl named Erin I had a huge crush on but I never went out
of there but you know what I’m going to add her to my list because I wish I went out with
her so I’m going to put I wish because you know she’s like the one that got away and
I had to be like sixteen by the time I had a crush on her for a long time what could
have been Oh anyways so now I have a longer list of constants right here so what we can
do now is go back in our main method right here and we’ll just keep this one right here
this is what we did in last tutorial but let’s see let’s go ahead and make a new line under
this for loop I mean we might as well keep this for a little it’s not hurting anything
and in case you’re just joining us this for loop pretty much printed out a list of all
the constants so let’s go ahead and just print out a line so we can separate this for loop
from our other for loop so system out this post system right system out print line and
let’s just go ahead and print something like um new line new line whoa whoa whoa what’s
going on up in here alright let’s just put and now for the range the hit caps ox embarrassing
constants so now we’ve pretty much got this for loop right here and we just got a line
saying and now for the range of constants so well we just want to be able to see it
easier so now let’s get to the meat of the tutorial and this is an enhanced for loop
to go through the range instead of the entire thing so the first thing that we’re going
to need to do is at the beginning of our class before our class we need to import something
we need to import the enum set class so Java dot utill the enum E and um se T and what
this is going to do is it’s going to allow us to use a built-in method called range – well
you’ll see what it does later I mean especially learn right just C so let’s go ahead and build
our enhanced for-loop now just like last time it’s going to take two parameters the first
one is what you want to name your things I’m just going to name those people what you want
name your objects now the second one is that method now we could just plug a regular array
in here but we want to have a range of the array we to start it let’s say Kelsey and
we want it to end it candy so I mean we can start and end anywhere so whenever like I
said before Java automatically gives you an array of constants in the order that you did
them in but in order to get just a specific set out of there arranged what you need to
do is this e num set period range and the range is the method and it takes two parameters
from is the first one so let’s just go ahead and write tuna which is the class Kelsey and
what’s going to do is look in tune class and find this first constant Kelsey and that’s
going to be your starting point and for – let’s just put tuna dot candy and let’s just go
ahead and show so now we have Kelsey to candy and everything included that’s what that does
it gives you a whole new array so now once we have that we can pretty much just copy
what we have up here copy thank you for that and we’ll paste it out here and so now instead
of an entire array which was two new values we have a specific set in the array which
goes from all the constants from Kelsey to candy so now let me run this and see what
we got that makes no I won’t expand it what’s the fun of that so now we have our first array
right here that has all the information Bucky – Erin that was the entire array and then
we says our line and then we goes i and now for the range of constants and we cut out
Kelsey Julia and Nicole and candy so using our enum set class and the method in that
called range we were able to provide it with two arguments we wanted to start and where
we wanted to end and this entire thing right here it gave us a new array so instead of
looping through the old array we’re able to loop through this new and improved array to
get only a specific set of data so that is your quick tutorial on my former love life
and also on how to loop through a specific range of an array using this range method
right here and again don’t forget to import this class or else you’re not going to be
able to use it so thank you guys for watching now you know all about enumerations constants
and how to loop the room and all and whatnot I know how exciting right so in the next tutorial
I don’t know where we’re going to talk about but I promise it’s going to be awesome so
you might want to subscribe just a little hint so thank you for watching and I will
see you next tutorial what’s up guys welcome to your 46th Jeff tutorial and in this tutorial
I’m going to be going over what static variables are and how they’re used so usually whenever
you have a class that has objects each of the variables um each objects has its own
set of variables like first-name and I can make um an object called Bucky in it would
have its own first name Bucky and I could have another object named Tommy and it would
have its own first name of Tommy but sometimes you want all the objects to share a single
variable for example if you’re going to make members of a club and you’re going to like
have the club count how many members were in it for example if I was in the club it
would be 1 if tommy was in the club it would be if me and Tommy we’re in the club it would
be – if me Tommy and Megan we’re in the club it’ll be 3 and we each don’t need to see that
we shall need an updated variable or a separate variable for 3 since the members in the club
is all the same so for example there are some variables that you just can share and you’re
saying alright why don’t you just write a separate variable for each object and update
it well that sticks a lot of time in space so you’ll see what static is by the end of
this tutorial and it’s one of the most useful things that I actually taught you so far so
listen up in this story we’re going to be building a club of course and the club is
going to be of hot girls that would like to go out with and yes they will be famous and
no I will never go out with them so let’s go ahead and make a couple regular variables
first for each object it gets own private string and let’s go ahead and put like first
the first name and then go ahead and put private string and last for last name and now we need
to give them a variable that they can share so go ahead and put private and put static
and that static keyword means that every object shares the same variable so when this one
changes it changes the all objects in before if you change one object’s first name not
only that object’s first name change but when you change a static variable they change with
all objects so if I change this to four then all objects would see four got it good so
static int and we’ll have members of our club and we’ll initialize the zero so without building
anything we have zero members in our club so next let’s go ahead and make our constructor
so public our class name is tuna and it’s going to take two arguments string first name
is string last name this is how we’re going to insert members in our club and in our constructor
just put first equals first name last equation to our members variable so after we add our
first member members will equal one when we add our second member members will equal two
so next let’s just go ahead and system.out.print format and our format will be something like
again you can be creative with this if you want umm constructor for make sure you spell
it wrong % s % s so it will be constructed for Bucky Roberts and then we’ll have members
in the club and then put like : % d and then a new line so we’re going to have like constructor
for Megan Fox members in the club one constructor for natalie portman members in the club too
easy enough so now we need to put first of course last and members and I spelled that
wrong I mean be ers members members that’s a pretty catchy dude alright now let’s go
ahead and write some more methods that are going to come in handy first we need something
to get their first name so public actually let me think about this for this tutorial
I’m teaching you is constructors right so we probably don’t even need these yet but
we sure do in the next tutorial so let’s go ahead and end in this apples and in our main
function right here let’s go ahead and make some members so let’s go ahead and make member
one tuna because this is into class member one and we’ll set it equal to new to none
in the course it takes the arguments again you can see what arguments it takes by this
constructor over here a first name and the last name so the first name can be megan in
the last name of girls I want a date club can be Fox so now what we should have outputted
on the screen is all might as well just do it constructor for Megan Fox and members in
the club one easy enough so let’s go ahead and make another one now tuna member to make
another object equals new tuna and we’ll have something like Natalie and then Portman you
don’t know who she is definitely Google it and let’s go ahead and make one more from
tuna member 3 equals new tuna and let’s see let’s get us let’s get Taylor she can join
the club too and Swift she is babe with a pretty voice hottie with body cutie with booty
anyways so we made three different objects each one well let me run this show you guys
that works show myself that it works so we made three different objects right here one
for Megan Fox named member one one for Natalie Portman named member two and one for Taylor
named member three each of them has their own set of variables let’s look at this one
natalie portman member number two for every object they have their own set of variables
right here natalie has her own first name right here and she has her own last name of
Portman right here but they all share this members variable and they cannot like Megan
Fox this object she can’t see what now these names are but she can see the members in the
club has changed it to and when Taylor Swift joins the club right here since its static
it means all of these objects share the same static variable so they can all see that the
members of the club has changed to three so that’s why static variables are useful since
you know sometimes you just need and again if you didn’t have this on a nutrient art
right here you would have to have a function to update all of these each time but you know
why update three separate things one two three and then when a member leaves you have to
update three Sep things one two three when you can just have one variable call it static
and update at one time so that’s your quick tutorial on what static is and why it’s useful
it pretty much instead of having to update it many times you just call it static and
all members or objects can see it so thank you guys for watching this tutorial if you
don’t understand you go in next tutorial because we’re going to be going over static some more
but like I said thank you for watching don’t forget to subscribe and I’ll see you next
time so guys welcome to your 47th Java tutorial and in this tutorial I’m going to be finishing
up talking about static members and also I’m going to be showing you a nice little trick
that you can use when accessing static members so go ahead and in your toon class or not
the class was not your main method in it class without your main method and there we go and
let’s go ahead and under this constructor let’s go ahead and build three other simple
little methods we’re just going to have one to return the first name returning last name
and returning member so public string and let’s just name it like get first it’s not
going to take any parameters and we’re just going to have it return first simple enough
and now let’s go ahead and make one for last name public string get last and guess what
we’re going to have this one to return last oh you guess that on a pad and now let’s have
one more and we’ll name it um it’s a public static remember this method needs to be static
static and gets Emmy and BRS I know I could figure out how to spell members get members
and then what are we going to have this one do let’s just have returned members so now
we have three variables up here a private first private last and a private members which
is static this method returns first name this method returns the last name in this method
right here it’s going to return the variable members so now that we have three objects
made go back in your main apples class or whatever you call it let’s go ahead and let
me show you how each member has its own set of data so let’s just go ahead and for housekeeping
sake put system.out.print line and let’s just go ahead and print an empty line right there
there because it’ll just be easier now let’s just go ahead and copy that because we’re
going to be using it I didn’t know we can do that did we and let’s just go ahead and
put what do we want to print on our first line and it’s really our first line because
this one’s just an empty line well what I want to show you that is even though they
all share that variable called members they each have their own set of data so let’s go
ahead and put member 1 which is our object 1 which is Megan Fox and we’ll put get first
and then let’s do this with last copy get last and was lesson called get members so
get members so here’s what’s going on now um make sure it’s going to print out yep so
anytime you call this one it’s going to have Megan Fox and this is unique to its own object
but it’s going to look at get members and see that it’s static so it’s going to share
this variable with all the other ones so depending on how many members are in this then that’s
what it’s going to print so let me go ahead and run this click OK and we have again we
have our other data that up there if you’re wondering oh it went but it says Megan which
is unique Fox which is unique in 3 which is shared among all objects so now let’s go ahead
and change that to 2 remember to remember to remember to now let’s go ahead and run
this and now you can clearly see Natalie which is unique Portman which is unique and 3 again
that 3 and that 3 is because this private static int static means our this variable
is shared between all objects so we don’t need to you know why would you make a separate
variable if it like anything how do put this why would you make a separate variable that
is going to be unique that we’re going to have to update in every object if it’s the
same value no matter what object to this so I mean you don’t need to so we’re not gonna
so that’s where static comes in handy and now let me show you that trick I was talking
about um since the variable static variables don’t change between objects static information
is value is available even when you don’t have an object so for example say forget about
all these objects right here and we actually can’t just delete them but we’ll delete these
right here and we can just add in this print liner really instead of calling a separate
object like an object and then your dot separator and then your method like that what you can
do with stack is just put the name of the class and put your dot separator and then
put your method get’ members like that now let me run this and you can see the three
right here can you guys see that the three right there so before we were never able to
do this we had to get an object and go to object anytime we want an access to any of
these members or any of these methods right here but with a static it’s a little bit different
because it’s not going to change from object to object since no matter how many objects
you have the variable is the same so that’s why I Java lets you instead of having to have
an object which you can do by the way what we just did you can also just put the class
name and put the static method ahead of that so again anytime you have a static method
that use static variables um you don’t have to have a separate object you can just put
the class name and then you can just put the method and that’s how like in arm stuff like
math like math functions and math constants on that’s how they do that so that’s just
a nice little tidbit of information so don’t forget that um static variables are shared
among all objects and that you don’t have to access static methods with a specific object
you can just do it with a whole class since it’s the same so thank you guys for watching
I think I confuse the enough for today but uh like I said thank you for watching don’t
forget to subscribe and I will see you next tutorial what’s up YouTube welcome to your
48th draft tutorial and in this tutorial we’re going to be going over instance variables
with the final like when you have like public final or private final int that’s where we’re
going to be going over so unlike static I’m going to be showing you guys what final means
so let’s go ahead and in your tuna class right here and this is the one that’s not your main
apples isn’t has my main method so go into another one I name my tuna you can name where
yours whatever you want as long as it’s a fish that’s key it has to be fish or this
program won’t work I’m just kidding but you know just a little joke and let’s go ahead
and the first thing we’re going to want to do is make a variable that’s going to be private
as well but you got to spell it right that’s key private there we go I know I get eventually
into some and what this is going to do is hold the sum of our numbers that we’re about
to add up now let’s like begin the tutorial what we want to do now is make variable with
the type final so private final and it’s going to be an integer variable and I hit button
there embarrassing and let’s just name it number or something and go ahead and put it
in caps because it’s going to be constant so we know that the constants aren’t caps
cook cook there you go cut cut that’s how you can remember it so now the key or what
final is is whenever you write final in front of a variable or constant it means that you
can’t modify this no matter what so we just declared it whenever we set it equal to something
whatever we set it equal to we can only set it equal to it once so if we put number equals
two then that number is going to be two for the rest of your life you can’t change in
Tamara watt but another thing is we declared it right there but we didn’t initialize it
which means we didn’t set it equal to anything so we’re going to have to do that in our constructor
so again you can either do right here or you’re in your constructor so let’s go ahead and
make a constructor put public tuna and just put int X it’s going to be a temporary variable
and then put number equal to X so whatever we pass in for our argument that’s what number
is going to be equal to and again don’t mess it up because you can’t change this you can’t
later in your program right all right we’re set it equal to two here but we’re going to
set equal to fifteen later on or eighteen or 32 you can’t you can only set it equal
to something here and it stays like that forever now let’s go ahead and build another method
so let’s go ahead and write public void make it called add because what’s it going to do
it’s going to take that sum that we have up here and it’s going to be zero default and
let’s just add the number to it so again the sum variable is going to change but this number
is always going to be like 10 or whatever we say this and now let’s just build one more
method so we can actually see what’s going on public string to string so again you learn
a to string method did last time whenever you need your object in a string format it
returns it so let’s go ahead and return string format and idly started filling out for us
the format just can be put some like sum is equal to percent D and then put like a newline
for good looks and then for your arguments just put some so this is going to change because
it’s the number that stays the same and not the sum and how do we know that because number
variable is final and sum is just private sum can change so now that we got that look
it over and make sure it’s the exact same as mine we can go to our our main class which
is apples in this case so go ahead and let’s create an object so tuna tuna object equals
new tuna and let’s go ahead and put something like 10 so now well this is going to do since
we passed in 10 to our constructor it’s going to take 10 for X put 10 for X right here and
set number equal to 10 so now for this object number equals 10 no matter what we can’t change
that so anytime we use number like at number 2 some we add 10 to some simple enough so
now let’s go ahead in well let’s go ahead and make a for loop using this object so let’s
just put 4 and let’s make a simple loop put like int I equals 0 if I is less than 5 in
I plus plus so it loops 5 times 1 through 3 loops 5 times it really doesn’t matter what
you have inside your for loop this is important just how to make make something real quick
now we can go sit ahead and say what do we want to do 5 times well let’s go ahead and
add on let’s call this a method 5 times so the first time it’s going to be 10 when it
adds it the second not time it’s going to add another 10 to it so it’s going to be 20
then it’s going to be 30 40 50 simple enough so let’s go ahead and add tuna object and
how you use it is add right there so now we did our method um five times but we can’t
really see anything because this method right here it doesn’t return anything so we need
to return it right here so let’s go go ahead and put system out let’s go ahead and let’s
do a print format and let’s just go ahead for the format we’ll put something like let’s
keep a simple % s and for the arguments let’s just go ahead and put tuna object so let me
go ahead and run through this and show you guys the results sum equals 10 some equals
20 30 40 50 so now let me talk you guys one last time why this happened make sure hopefully
I’m in my screen recorder and good enough so what we did is we made two variables well
let’s just go ahead and do this way we made an object called new tuna or tuna object was
the name of our object and we passed the parameters 10 for the constructor so it took that 10
and set number equal to 10 all right simple enough what’s next well we loop through this
five times so what did we do five times we did this add method five times so first four
add it took that number ten and added some so now sum was equal to ten then it just spit
out 10 and then the next time on round number two it took that 10 and added it to 10 then
we got 20 so now it spit it out 20 then it took 10 and added to 20 which was 30 then
added it to 30 which is 40 then added it to 40 which is 50 so now that that’s all done
so that is pretty much your really detailed tutorial on a really simple explanation that
whenever you make a final variable you cannot change it so for example if we say down here
um tuna object number equals 15 look at this right here we get X right here the filled
tuna number is not visible that means that it can’t change pretty much so that’s pretty
much all in all I could have skipped this whole tutorial and set our when you’re right
final instead of a variable it means you can’t change it but I didn’t I decided to give you
guys the whole spiel instead so thank you guys for watching and hey if anyone wants
to do fantasy football with me um leave a comment and let me know because I wanted to
fantasy football with someone so thank you guys for watching and don’t forget to subscribe
and I’ll see you next time so guys welcome to your 49th Java tutorial and in this is
order I’m going to be talking about inheritance now what inheritance is is pretty much inheriting
stuff from another class so why is this useful well say we have two classes right here tuna
and potpie and in the tuna class we have a method like public void we’ll just name it
eat and let’s say armed in this method all it does is go system.out.print line and then
it just print something like I am the eat method and safe we had a bunch of different
little food classes and every single food class had this method so tuna had it and potpie
had it and say we had a bunch of other ones like chicken liver ham they all had the same
exact eat method so then your boss comes in and tells you all right you know when you
wrote the eat method say I’m the eat method well we actually want you to say I am the
e methods with s so now you got to go in every single different clef class and change that
one method and add an S on the end and you’re saying alright I wish instead of having all
these copies that I would have to maintain if I could just have one single copy so that’s
what exactly inheritance is instead of having all these copies and different classes that
you have to maintain you can only have one single copy that you have to maintain in each
of these classes can inherit that so let’s go ahead and copy this and since tuna and
Popeye or both foods I made this new food class right here and what this food class
is going to do is it’s going to store all the things that tuna and Popeye have in common
and right now they have this eat method in common so we can go ahead and get rid of this
method right here and get rid of this method in here and instead of having all these separate
methods in all these classes we only have to maintain this one method in the food class
so how exactly does this work and how can we only have one method to kind of take care
of well this is what inheritance is instead of having a bunch of different methods what
this tuna class and Popeye class can do is it inherits everything the variables and methods
from this main food class and whenever we do this the kind of methods that inherit the
stuff those are called the subclasses and this stuff that they or the class that they
inherit from is called the superclass so again these two tuna and Popeye classes are going
to inherit all the stuff that’s in the food class and the food class is called the superclass
in the tuna and Popeye class are called the sub classes so how exactly do we inherit everything
well instead of saying inherit from what Java said is it gives it a new keyword name extends
ext BND s and whenever you write extends this means inherit from so say public class Popeye
extends food this means all right in this class potpie we’re going to in hair everything
from food so we’re going to inherit any variable that would be in hair in all the methods so
let’s go ahead and do that same thing from tuna so public class tuna this class ext inds
it extends food so now anything that’s in food is inside Popeye and tuna even though
we can’t see it that’s what we mean so let’s go ahead and let me show you guys that right
now so say we go or whatever your main method is right here let’s go ahead and make a object
so I’m going to make my tuna tuna object and let’s just go up ahead and put new tuna let’s
just go ahead and make the same thing with top pie so pop pie PAH object would be JCT
and I’ll figure it out eventually new popeye so now we have a toon object and a potpie
object sure I didn’t mess anything up so now even though we have no methods in here they
inherited all the methods from food so we would use those methods just like we would
anyone else so this method is called eat don’t remember and it’s in pot pie and tuna even
though you can’t see it so let’s go ahead and put tuna object eat and pop pie or what’s
called pot object eat and see what happens and we’re getting a error right here oh we
forgot to equal sign there we go and now when you run this we see I am the eat methods and
this one came from tuna and this one came from PAH object so that’s how you can have
you can hare inherit all the methods from another class using the extends keyword but
what if you’re saying alright you know I have a bunch of different foods and I know we only
have two foods right now this is just them trait but I’m saying alright I have a bunch
of different foods like tuna potpie chicken liver but I have this one class called tuna
and I want to inherit all the stuff from food but I want to change this one method right
here well what you can do is override certain methods and in order to override certain methods
you just put the method into the class the subclass and you recreate it so then if you
say all right I am the new method of tuna so make sure you spell a couple things wrong
there and now whenever you override something you inherit everything from the food class
but the methods that you recreate they’re going to override or overpower the methods
that you inherited so now if we go ahead and run this we see this let me get it up for
you there we go I am the new method of tuna and this is the method that we overrode and
again the it’s the easiest thing in the world whenever you want to override something all
you have to do is pretty much just create it again and then you don’t have to worry
about you know well it’s pretty much as simple as that I can’t explain it any better but
that’s how you override something in PI objects we didn’t override that method so that’s why
I got the default food method and then the last thing or the last couple things I want
to talk about real quick if say tuna extends pot pie and pot pie extends food then tuna
inherits all the stuff from pot pie and food it’s like a little hierarchy so let’s go ahead
and delete this and now when tuna extends Popeye and inherits all the stuff from pot
pie and food and the last thing I want to take note of is that only let’s go ahead and
get rid of one of these objects let’s go ahead and get rid of the pot object only the public
methods can be inherited let me see how much time I got left two minutes only public methods
can be inherited so if you have a private method in the superclass again the superclass
is the one that the subclass inherits from and we want to change that to food so right
now tuna is inheriting all the stuff from food but food has this method in here that’s
private what private means is all right you can’t inherit this from me in order to inherit
it it needs to be public like we did before but when we put private like this and try
to run this right here we get a little error right here and it says the method eat is not
visible so whenever we try to run it I’ll show you the syntax error down here and then
pretty much this is saying all right this isn’t visible because food has a private thing
that you tried to inherit in news and you can’t it’s private it’s not public so that’s
your real quick tutorial on inheritance and pretty much anytime you want to inherit crap
from another class just write extends and extends is this a real fancy word for tuna
inherits from food or tuna inherits all the methods and variables from food and again
well that’s it for this tutorial I already filled your brain with enough so that’s your
real quick tutorial on inheritance I hope I made it simple I hope you guys can understand
so thank you guys for watching and I will see you next tutorial what is going on people
welcome to your 50 Jeff tutorial and I know it’s been a while since I started making Jeff
tutorials but hey we’re going to get back on track and start learning some more Java
so actually I had planned out that we’re going to learn polymorphism but I think I’m just
going to skip right to GUI is because it’s a lot funner and it’s better if we know how
to make an interface before we start getting into some other stuff plus one we have an
interface and stuff you can see what everything does and you’re not just typing random code
that you’re like all right what is this the matrix because you know it’s time we started
building an application that the user can interact with in C so if you don’t know what
a GUI is or some people call it a GUI it’s a graphical user interface and just like this
right here it has title bar at the top menu dropdowns has a whole different range of buttons
and that’s what we’re going to be making instead of this right here where it’s like matrix
style because I mean come on it’s 2009 if you’re watching this story on 2009 that is
so let’s go ahead and get started now the first thing you need to know is that all gooeys
are built from GUI or GUI components that means there has to be a component for a menu
a dialog box scrollbars you have to add each one of those individually so how do you just
go ahead and get these components well actually Java has built in a class that stores all
the components you need you just need to tell it where to put it and what to do with it
and they are created using different methods in the methods used to create this in the
class it’s called the J option pane class now like I said this class is built in the
Java so anytime you want to make a button all you need to do is call it from the class
and there are different ways to do this but this is the easiest way so in order to get
all those buttons and toolbars in everything we first need to import the entire class so
let’s go ahead and before your evening class right here just go ahead and put import Java
X dot swing dot J option pain and make sure you type the J in the o capital option paint
and just like that and now we’re getting a little error that says on the import Java
Japs from pains never used so let’s go ahead and fix that by using some stuff right now
so now we imported the class which means we have access to all the crap in it so let’s
say we’re using something that career the first thing we’re going to want to do is set
to variables by the way I’m going to build program where you enter a number in one box
and then click OK you enter a number in another click ok in the end box the third one shows
your answer you’re seeing a little bit so we need to set this equal to string variable
and set it equal to first number and I’m just going to write m then R excuse me FN for first
number now what you need to do is called the class which is J option pane use your period
or dot separator in the method for an input dialog is show input if you can’t tell by
these hundred pop-up things that pop-up dialog and it’s going to take one parameter right
here and this is the message now what this is is the message or the prompt which you
want to tell the user to do so we just want to put in a string enter first number so now
whatever they enter into that first number is going to be stored in variable FN so now
we need a second number so let’s go ahead and copy this press ENTER paste it and let’s
just set string second number and we’ll just put ekit enter second number right there make
sure I got my whatever it’s called semicolon and let’s go ahead and move this over here
because just because I feel like it now here’s a little thing that you need to know every
time they enter something in here show input dialog method only is able to get a string
so we can’t add strings strings are pretty much letters in numbers that it doesn’t see
as a number so we need to tell Java all right instead of viewing this as a string we want
you to view it as an integer so you can do some math with it later on so what we need
to do is convert these variables to integers so this has nothing to do with them J option
pain this is just Java right here so Java num or excuse me int num1 equals its Jerk
dot parse int and what this does is convert whatever I type into here in stores is an
integer in num1 so I want to put FN and what this does is take the string which say it’s
5 and converts it into the number 5 so now let’s go ahead and do this for num2 num2 we
want to take the second number we typed in and convert it to a variable called number
2 so now the last thing we need to do is just show the sum so before I even do that let’s
just add the sum in sum equals o to put num1 plus num2 no spaces and now we got the final
answer in the sum variable right here let’s tighten that up a little bit that’s what she
said and now we can go ahead and display this now the box that you used to display is something
called show message dialog so let’s put J option pain the show message dialog and this
is a little different than show input dialog inputs for inputting messages for displaying
now this method takes 4 parameters the first one is it’s a parameter where to position
it and if you put null positions at right in the middle of the screen the second one
is what you want to say like for your prompt but isn’t prompt it’s just a message so let’s
put the answer is and let’s just put add some so it’s going to be like the answer is 5 or
something like that now the third parameter is what we want to appear on your title bar
so let’s put like the title or something something easy like that and the fourth parameter you
need is the message that’s going to pop up now I’ll go over this later if I got time
but for right now just put J option was a pain then put plain underscore message like
that and you don’t need to put this last thing in quotation marks so again well that’s pretty
much it let’s just go ahead and run this program tire waiting around so let’s go ahead click
OK run it enter your first number three okay enter your second number five okay the answer
is eight and now I can talk you through this one more time so now once we go ahead and
run this what we’re getting is this very first thing the show input dialog and it says enter
your first number and we’re going to go ahead and enter four press ok now once we press
ok it stores that four and F n variable right there and also it allows us to move on to
this other show input dialog it doesn’t move on until you complete the show input dialog
so under your second number six okay so now what it did right here is it took that four
and convert it to number and took that six and convert it to a number so that you can
add the two sums right here and lastly it took that show message dialog which if I can
get it back right here and it says that know what main position in the center of our screen
the answer is some right here and again that third parameter was the title which appeared
on the title bar and that last one you have the option of putting icons on your um GUI
or user interface that we built but we’re not going to put like ons on here now mostly
could because they’re stupid um if you want to have something like an error you can put
X on there a warning you put it like a I don’t know they’re stupid but we’ll probably put
them in next time because I’m stupid too so but that’s a real quick tutorial on how to
use J option pain to make a simple graphical user interface aka GUI so in the next tutorial
we’re going to be building our gooeys and atom some more function ask more cool buttons
and stuff like that so thank you guys for watching don’t forget to subscribe and I will
see you next tutorial what’s going on guys welcome to your sixty
first job tutorial and this tutorial is probably going to be the last tutorial for now on polymorphism
oh so I flew so in the last couple tutorials I told you guys about the concepts of polymorphism
and I showed you guys how to do some pretty cool stuff of them but we never really put
it into a program and we never really got to see why this was really useful so in this
program I’m going to show you pretty much the core heart of polymorphism and what you
can use it for so let’s go ahead and in this program I’m going to make a method in each
one in these classes that’s just going to say I don’t know I’m going to have like a
line for fish that says make a noise I’m going to have a line for dog that says make a noise
and by line I mean method and also one for animal as well so let’s go ahead and make
the same method and animal fish and not dog and I probably should have made an animal
that makes a noise besides fish but you know fish don’t really make noise but that’s not
important you’ll see what this tutorial is about so let’s go ahead and make a method
in here for an mo and we’ll put public void noise and since animals don’t really make
a noise let’s just have something on the screen because this method is actually never going
to be called but I just want to make a method to show you guys it’s not going to be called
so system.out.print line gotta learn to type print line and we’ll say like animals don’t
make noise and this is pretty much a point of inheritance and why we have this um class
right here because fish and dog are each since they extend this they can both override this
method right here so let’s go ahead and copy this in the fish one let’s go ahead and put
the same method in here again we don’t change your name of it it’s just the noise one but
it’s coming from the fish class now and what kind of noise does a fish make put like blurp
slurp that’s what noise I’ll make if I was a fish so you know it’s good enough dog one
should be a little easier we’ll put a method in dog called boys as well and will make this
one go grow not rust rough right like that so now we have this method called noise and
animal and we also have a method called noise and fish even though fish don’t really make
noise but this fish says glib slurp and we have one in dog called noise called a ruff
so we have this main method and animal and it gets overwritten when you call it in dog
and fish so now um that we have three methods named the same thing let me show you guys
the core heart of polymorphism one of the main aspects of polymorphism is that it you
can put objects in wood an array like we did last time but we didn’t really do anything
with it we just added them into the array the cool thing is that you can put objects
in an array and you can loop through that array and call the same method for the objects
the thing is you can automatically call a noise for dog and when you call noise for
dog ruff prints out and when you call noise for fish glare slurp comes out and if we had
a burden you call noise for bird it’ll be chirp chirp if we had a class called cow and
the math Conroy’s oh do Moo so it’s pretty cool in the sense that you can loop through
an array of objects and call the same method arm the same method name but each method since
it’s in a different class it does something a little different and this is my virus protection
right here so I will renew that later get on my way get get so let me go ahead and show
you guys how to do this go ahead and make an animal type object which is actually going
to be an array so go ahead and write animal and one name in the list and we’ll set equal
to new animal too and again the concept if we have an array of type animal then not only
can we put animal objects in it but also fish and dogs and say extend animal and that’s
one of the concepts I tell you guys before now we can actually put it to use into something
useful so now we go ahead I mean we need this is going to be a rate of objects of two objects
so actually this is three but let’s go ahead and make a dog object and the fish object
to use it I can go ahead and change it well it’s good so dog D equals new dog with empty
parameter since then I have a constructor or nothing so fish F equals new fish no parameters
for that either so now we have an empty array in two objects D for dog and F for fish so
let’s go ahead and use those right now we’ll just uh do this the easy way the visual way
so at index zero which is the first element let’s just go ahead and set that equal to
D for dog and at the list and then index 1 which is the second element set the equal
to F for fish now let me get this out way this is annoying so now we have an array and
we have two elements in it and again if you watch the last tutorial you can see that you
can populate this array using add method but this is just a really easy method method for
demonstration the next thing I’m going to do is write one of these enhance for loops
and in case you forgot want to enhance for loop was it pretty much is a special loop
to loop through an array so first you put animal and then you give a new variable what’s
going to use X it’s kind of like the counting variable in for loop and then you write the
array name so now it’s going to loop through the array the list and every time it loops
it’s going to treat the index as X so we can do things like this X which is the object
now since we put objects in the array so this would be substituted for D the first loop
and F the second loop and then you should be X dot noise and what this is going to do
in essence it’s going to loop through the entire array and it automatically knows the
length of it so you don’t got to worry about counting variables or anything the first thing
it’s going to do is say alright what’s the first element in the right it’s a dog so I’m
going to put dog dot noise and I should have ruff print allen screen alright done with
that now next element in the array it’s a fish element so I’m going to but fish noise
and the fish noise is glib slurp and then I’m done and that’s it so let me go ahead
and run this to all those then you see ruff glare slurp so that like I said is pretty
much the core essence of polymorphism in the sense that you can automatically create an
array of objects and loop through that array and call each method with the same name in
that object and you don’t have to create a bunch of objects you don’t have to be like
D dog F fish this is a real quick way if you have like 100 or excuse me and 100 what I
keep saying in hundred a hundred objects so you don’t have to call a hundred lines of
code you can just make this and it loops through so in the next couple of tutorials I don’t
feel like doing any more polymorphism because kind of annoying ant but I needed to teach
you guys with like implements and abstract classes were so that’s why I did this because
in the next tutorials we’re going to be getting the gooeys more and some awesome visual stuff
so thank you guys for watching this tutorial don’t forget to subscribe the next tutorials
are going to be awesome so again thank you guys and I’ll see you next time what is going
on people welcome to your 60 second java tutorial and in this tutorial we’re going to be getting
back to what everyone loves most and that is gooeys so as you can see I already created
a new class called GUI and I already went ahead and imported everything and you should
all know what this stuff means for my last tutorials I just didn’t feel like um having
to type it all again you guys didn’t want to watch me type it anyway so I went ahead
and imported everything we need to import we’ll figure out what these do later so if
you watch my other tutorials you’re already know what to do but anyways go ahead and make
a new class called GUI and have it extends jframe and I’ll leave that up if you guys
want to copy I guess and what extends mean is it pretty much inherits everything from
jframe and we’re going to be making buttons in this tutorial in jframe has some built
in stuff for us to create buttons and the first thing we’re going to need to do is create
two variables so go ahead and put private j button and we’ll create two buttons first
one will be a regular one and then we’ll go ahead and create another one J button and
we’ll just make this one a custom one one of them is just going to be a regular button
in other one if we spoke private right it’s going to be a button with our own images on
it and I’ll show you where to put the images and how to do all that good stuff so I’m going
to go ahead and minimize this so hopefully you guys have that copy down because it well
just because it’s annoying me so the first thing we’re going to need to do is build a
constructor so go ahead and put public and just go ahead and put GUI or whatever you
name your class right here and we need to build a constructor because whenever we create
an object from this class we want this window to automatically pop up we don’t want to have
to call a method for it to pop up so go ahead and add no parameters and in your constructor
body this is where we’re going to be doing the meat of the programming the first thing
we’re going to want to do is add a title now this super right here this super keyword is
how you call methods from the superclass so since we’re extending jframe this is the jframe
constructor so go ahead in the constructor for the jframe is pretty much the title so
go ahead and write the title so um you know you guys didn’t need to know that all you
guys need to know is in order to add a title to your window just put super the title I
just want to tell you guys um if you don’t know what the super does it allows you access
to your super class so you know a little bit of information for everyone so now that we
have a title on our window we can go ahead and make the layout for the buttons we do
this set layout and you guys should know this still from the last tutorial when you’re working
on gooeys and we’ll just go ahead and put new flow layout just like that and now this
just gives us a default layout so we don’t have to code it ourselves and now let’s go
ahead and add our first button to our screen so we’ll take that variable we made I am named
my reg you can name as your wood you can name yours whatever it was new J button in this
J button method is a method to add a button and it takes one parameter for here and it’s
pretty much the text that’s going to be on the button I’m just going to name it a reg
button so now if we go ahead and add this to the screen we now have a blank screen that
has a title of the title on the title bar and we have a button that says reg button
on it well that’s pretty good pretty neat but we can do better let’s go ahead and make
a button using our own custom picture in it and when you roll over it you get another
picture so the first thing I want to show you guys is that I have two pictures already
um right here and how did I get these pictures here so I can use first of all I want to tell
you guys when you create your buttons make them like 40 by 40 and make sure you save
them as ping I tried to save them as gif or JPEG and ping is the only one that like gave
me so it could work all the time it Java supports like a gif and JPEG and all the regular image
file but for some reason only pin was working on my computer maybe it’s vista thing maybe
it’s not but once you create these images here’s where you put them go ahead to my computer
and you need to find the files you’re working on these class files mind the default workspace
are insi users Greg and then is in a workspace and go ahead and go to let’s see mine is in
Bucky source and then this is where all your class files are like apples that GUI one we’ve
just created put them in the same directory is that so then you don’t have to write a
bunch of image paths you can just write the file name in you’re good go so your workspace
might be a little different and if you don’t know where your workspace is as soon as you
open eclipse it tells you where your workspace is so just copy that find it and that is where
you want to put your ping files right there so now that you got your ping files in your
same directory is your class we can go ahead and uh well make some fancy buttons so let’s
go ahead and how you do that is in your icon class and you have to name it icon go ahead
and give it an object name such as B and what we need to do is put new image icon and this
is built-in so you can’t change any of this let’s go ahead and get class which is this
class and then put get resource and this resource is going to be the file and the resource is
going to be well I named mine be ping and what this does is pretty much take that image
and save it an object named B so now we actually have two images or at least I do have one
named B and one named X so let’s go ahead and create a new one by pasting that in icon
X is equal to new image X dot ping if you’re wondering all right what’s this beat-up ping
an x-up ping they’re actually just two images I made in Photoshop earlier so you guys won’t
have them on your computer but I just want needed a little something to test on so that’s
what I did so now that I have an image named B and an image named X I can go ahead and
change those in the buttons so what I’m going to do is take that custom button remember
I named a custom out here and do custom and for the value I’m going to set equal to a
set equal to nu J button and for my parameters it first takes the name what’s on the bun
and I’m going to name a custom and for the second parameter this is optional parameter
you can have the image you want to appear on the button as well so I’m going to have
B and this is pretty much just a little graphic it’s a 40 by 40 graphic and it’s like well
I guess you guys are going to see and another cool thing that we can do with it if we said
all right on that on the button we just created there’s an image okay I got that but what
are you going to do with this X image right here well that X image is going to be the
rollover for it so whenever we do whenever we want to create a rollover what we do is
type the name of that button right there and you need to put set roll over icon right there
actually set rollover I selected around one embarrassing and the argument for this is
of course the image you want to roll over and now let’s just add the custom button to
the screen so now we got two buttons on the screen right here we have a regular button
and we have a custom button so in the next tutorial we’re going to be creating a class
too so when we click the button it’s going to handle the event and we’re also going to
be um you know that’s it we’re going to be seeing these buttons in action so and I’ll
also go over everything I did in case I kind of confuse the by gone too fast but for now
my tutorials getting too long so thank you guys for watching make sure you check out
the next tutorial where we see these buttons in action so again thank you don’t forget
to subscribe and see you next time what’s up guys welcome to your 63rd Java tutorial
and in the 60 second Java tutorial we made two buns and put them on the screen one right
here and one right here so now in this story where we’re going to be doing is building
um some kind of handling events so when we click the button something actually happens
so we’re actually going to be building a whole new class called well we’ll name it something
like handler class but for now we’re just going to be creating the object for it so
let’s go ahead and put handler class and we’re probably going to be getting an error right
there and we’ll name a handler object equals new handler class and why we getting error
because we didn’t create a class named Henry alert class yet but trust me we will so now
let’s go ahead and add some action listeners so Reg which is the name of the first one
we’ll just go ahead and add action listener right there and for the parameter it takes
the object handler so that’s why we needed to create a class before or excuse me an object
before we created that class Handler and let’s go ahead and just add the same thing to our
other bun which is named custom there we go right there and what this pretty much does
add action listener is pretty much the beginning of adding a pretty much a handler for our
buttons so anyways we are let’s see I think that’s everything we needed to put in the
constructor so this whole thing right here is your constructor right here so we want
to build another class called handler class but let’s build it outside of the constructor
so and your parentheses and outside of your constructor now let’s add some space right
there let’s go ahead and type private class handler class and we need to name it handler
class because we name this Hanover Clause right here if you name something different
up here create it a create the same done here and yes we are putting a class inside this
main class we are allowed to put classes inside classes so you know just letting you know
we can do that why because we just did and we’ll have this implements there we go did
I spell there implements action listener and when a class implements another class what
does that mean when a class implements another class like we’re implementing did I spell
that right I was wondering I was getting line when we have a class in the implements action
listener what does implement means I had a couple of questions asked me on the other
tutorial what implement means in a nutshell is we’re saying to action listener all right
we want to use your class in your method an action listener says all right if you implement
me I’ll let you use my methods but you have to over write every single method in my class
and we’re saying alright we’re going to inherit air all your classes from you but we promise
we’re going to overwrite it and it’s a little more complex than that but in a nutshell that’s
basically what it means so now any method that’s in the actionlistener class we’re going
to have to overwrite it and create one or so lucky for us there’s only one method in
the actionlistener class and this is called action performed so lucky for us we only have
to create one method and it’s going to overwrite this action performed method so let’s go ahead
and do that right now we’ll set it equal to public void action performed just like this
and as a parameter it takes action event event so that’s all we have to do and in the method
body what we write in here is what we want to happen when one of these buttons are clicked
so since we added the functionality of add action listener class to handler it pretty
much whenever we click this button this happens and that’s where we’re going to create right
here to functionality for it so whenever we create regular this is going to happen whenever
we create custom this is going to happen so enough talking let’s just go ahead and do
it what we want to happen is we want J option pane to pop up which is pretty much a separate
window and we want to show message dialog and I didn’t feel like typing it because I
was lazy so I just did that and this takes a couple of parameters itself and that is
null and that’s just positioning and let’s just go ahead put string format put some text
on the screen first one will be nothing fancy just % s and the second argument will pretty
much be event and you’ll see what this does later on myself press for you get action command
just like that and now I just got to make sure I don’t have any errors and now with
that we don’t we can go ahead and we can call this main pretty much class so go ahead to
where your main method is for the whole entire program because that’s where we’re going to
be doing now as you can see you need to import Java X swing jframe and this pretty much lets
you use windows i already imported it because i didn’t want to have to forget so now we
can go ahead and make a GUI object so GUI or whatever you name this class I’m going
to name my GUI object geo for GUI object equals new GUI doesn’t take any parameters in the
constructor and now just put go set default close operation and you definitely need to
have this or else your program is going to be able to close and then you need put in
here J frame dot exit on close so make sure you have that it’s pretty important if not
that I spell something wrong is oh here we go is undefined for the type of GUI set default
close per patient there we go spelling its key kids it’s key definitely need learning
that skill in school unlike me so the next thing I want to do is pretty much set the
size for our window do we do this with a set size billon method and you can set it to anything
you want I’m going to set mine by 300 by 200 and the last thing is you need to make sure
it’s a visible so go dot set visible and it’s boolean value just set equal to true if you
set it equal to false and won’t show up and we do want to show up so let’s go ahead and
run this right here and here’s what we see we see a regular button right here that when
we click it it says reg button and we see a custom button that when we hover over it
the roll over changes and when you click it it says custom okay regular bun custom wow
this is an awesome program we should definitely market this try to sell it to Microsoft or
someone because they could use this I mean look this flawless no bugs or anything that’s
amazing so now let me see time I left have left on my tutorial two minutes I’ll give
you guys a quick little walkthrough of how this works again I’ll just give you guys the
meat of the tutorial we created two variables and those we’re going to be the store or buttons
next thing in our constructor we added a title to our window we gave our window a layout
which is pretty much default layout we added a regular button as you can see here and then
we made two images and we store them in objects B and X and then we pretty much in added another
button a custom button with the image B by default and when we roll it over it we got
the image X and we added it to the screen lastly we created a new class which pretty
much was the to handle the events when we clicked our button we set our right for this
regular bun we want to have an event when we click it and for this custom button we
wanted to have an event when you cooked it so they just weren’t pretty much playing on
buttons just sitting there do nothing and then since we said our right we want some
functionality we actually had to make a class to add some functionality to it in this event
get action command this pretty much just gave you arm the name of the button so that’s pretty
much all that did um real basic stuff here and the next tutorial we’re going to be going
over some other stuff for gooeys as well we’re probably going to be focusing on seong-gu
ease and event handling for a little bit since you know it’s pretty much one of the coolest
things in job what we can do so thank you guys for watching this tutorial don’t forget
to subscribe and I’ll see you next tutorial what’s up guys welcome to your 64th java tutorial
and in this tutorial i will be teaching you guys how to add checkboxes to your GUI and
yes it’s going to be awesome so pay attention so I already got my imports right there if
you want to copy those go ahead but I’m going to go ahead and minimize that right now so
if we need a copy and pause your screen but if not see you later they’re annoying me so
now I already made this class called GUI and it extends jframe like before but I got rid
of everything in the class so now I can go ahead and start well pretty much making everything
again so in this program we’re going to build three variables one’s going to be a textbox
with a sentence in it and we’re going to have two check boxes underneath one that says bold
and one that says italicize and whenever we could click bold it’s going to bold the text
and whenever we click italics it’s going to italicize the text so we need three private
variables so name private J text field and this is going to hold the text and we’re going
to name this TF for text field and we need two more private J check box make sure ispotter
eight don’t want to spelt like the Czech Republic check box and we’ll just name this like bold
box because this one’s going to be the one in bold and private and it’s going to be another
check box why did I just not copy and paste that and this is going to be like a talaq
box or something like that so now we have three variables that are going to hold the
text field the bold box in the check box once the text field to our check boxes so now let’s
go ahead and well I guess we can go ahead and build our constructor now so public GUI
and doesn’t take any parameters of course and let’s just go ahead and first thing add
the title of course super just put like the title and the next thing we need to layout
set layout and or up just a future heads-up Ruby actually going over how to make custom
layout in and a couple tutorials but for now we’ll just go with the default because you
know works pretty good so new flow layout will give us the default layout and now we
can go ahead and start adding stuff to the screen so that text field we want to set equal
to nu J text field and as our parameters the first one is just right this is a sentence
or something like that with the size of 20 and that pretty much gives us a text field
in the TF variable and now let’s just go ahead and we can do stuff to that text field now
the first thing that we want to do is pretty much set font to it so let’s just go ahead
and set font like just make it actually do this to put new font there we go and as your
parameters put serif and don’t put anything else because Java only accepts um a couple
weird one so font plain and plain means like not not bold and not italicize or anything
in the size of 14 so that’s how you set the font you set the font with new font method
and it takes serif and make sure it’s safe because I know for a fact that serif no matter
what version of Java or what platform you’re running on it’s going to show up so make sure
you do it serif just like that and now that we got a text box with it says this is a sentence
we pretty much have all the text now all we have to do is add it to the screen so add
TF I mean it would be a waste if we created all that and we didn’t even add the screen
so now we got that text field right there now we can go ahead and make our two little
check boxes to add the screen underneath it so let’s go ahead and make bold box or whatever
you name your variable and let’s go ahead and set this equal to nu J check box just
like that and the parameters it takes any time you make a check box there’s going to
be a little thing to the right-hand side of it or else you’re not going to know what the
heck it does so it’s like a little prompt to tell you what this tech box does or a check
box does I’m just going to say bold because I mean you don’t need any more instructions
than that and let’s go ahead and do the skin with the italic box so copy this because we’re
lazy and paste it and italic box I think that’s what I named it yep and put italics or italicize
or something like that and now let’s go ahead and add both of these this screen add full
box to the screen and add we scroll down a little bit there we go right there add italic
box to the screen there we go so now we have pretty much three things on the screen a text
field and two check boxes underneath it the thing is they’re just chillin on the screen
right now not really doing anything so what we need to do is add some functionality to
it so just like before we’re going to create a new class called handler class and we’re
going to name the object Handler and set it equal to new handler class just like that
and even though we didn’t create that class yet we’re going to use it later on so now
let’s go ahead and add an item listener for it so bold I’ll go to in bold box dot add
item whoa whoa whoa I did not mean it like that add item listener and what are we going
to add it takes an object as its parameter so let’s just add handler so now let’s do
the same thing actually copy and paste in it Susan time copy and paste now and do the
same thing right here with italics so this pretty much now that we have added an action
or excuse me an item listener we have a listener waiting and what this does is pretty much
waits for something to happen to bold box or italic box and the only thing that can
happen is you can click it so now something is going to happen and it’s going to wait
to be clicked and when it gets clicked it’s going to recognize that it gets clicked so
now that we are able to recognize one that gets clicked let’s go ahead and make something
happen when it gets clicked I mean can recognize it so might as well so the first thing we
need to do is create a private handler class so private whoa whoa whoa not right there
right here private I cannot type today handler class and implements I spell that right item
listener like that and you don’t want in for our body upper class just like this actually
in the next tutorial I’m going to show you guys what goes in the body and it’s pretty
um different than less tutorial so you guys definitely want to pay attention to list but
another thing that I want to point out before I forget whenever you put a class inside another
class and if you’re saying alright Bucky how come you just don’t put this class outside
right here and make twos totally different classes how come you need an inter class to
go inside this whoa if you put a class inside another class then this class this inner class
it can see all of the variables and the methods in the outer class so if you were to make
two separate classes either on the outside of this or in a totally different file then
it’s not going to be able to see the variables and methods and since we want to make this
class use some of the methods and variables in here that’s why we need to put this class
inside the bigger class right here so that is why I put this handler class inside this
GUI class or GUI class but again and the next story I’m going to show you guys add some
functionality to tell you guys when you click this check box here’s what happens when cook
the other one here’s what happens when you click them both here’s what happens to the
text but for now that’s it for this tutorial I’m running out of time so thank you guys
for watching and I will see you next time what’s up guys welcome to your 65th Java tutorial
and in this tutorial we’re going to be building a new class to handle the events when both
of our check boxes are checked so let’s go ahead and make a new class called handler
class to do just this we’ll go private class name it handler class there we go get eventually
implements I got a type so EMP implements item listener there we go now what this does
pretty much is a class that implements item listener and what implements mean is we get
to use all the methods from item listener but we’re making a promised item listener
item listener says all right here here’s what would happen if they’re having a conversation
item listener BIC all right you want to inherit from me fine you can but promise if you implement
from me you have to overwrite each one of my classes so look at this it says the type
hand handler class must implement the inherited abstract method so there’s abstract methods
in item listener that we need to overwrite pretty much lucky for us there’s only one
method in item listener not very big class and this method is called item state changed
so let’s go ahead and overwrite this favorite right now so public void item state change
right like that make sure you spell it right if not you’re going to have some problems
and the parameter it takes here is the item event event object so what’s going on pretty
much is this every time you click one of these checkboxes essentially attach them to item
listener something calls an item event occurs or pretty much an event occurs now what we
can do with this event is add some functionality to it and it can be handled by an item listener
object which we created so now whenever since this item listener is listened linked to this
bold box whenever an item event occurs it’s going to run whatever is in here so let’s
go ahead and make some code to put in here first of all we’re going to want font name
it fun instead of equal to null and this is pretty much just going to store the font that
we’re going to change so what we want to do is say all right if you click the bold box
we want to bold if you click the italic box we want the font italics if you click the
bold box and the italic box we want to bold and italics if nothing’s clicked just have
plain font so let’s go ahead and ferd right if bold box dot and the thingy rate is is
selected just like that and this is built in method to show if it’s checked or not so
if bold box is selected and let me find it and it’s out what a name italic box dot is
selected then what do we want to do well let’s go ahead and change that font equal to new
font and we’re going to be doing a lot of copy and pasting after this we want to change
it to new font first of all we want to make it serif just like before I want to take that
font and make it bold and actually we need that all in caps I forgot and we also want
to take that font make it italic and then we want the size to be 14 so get on my way
house so what this means if you press the bold box and the italic box if both of them
are checked then we want to change the font to bold and italics so what other options
do we have here whoa we have else if we can also have an option that if only the bolt
box is selected so let me tighten that up so actually we can just go ahead and copy
this little too easy so else if only the bold box is selected then what do we want to do
we want to take that font and set it equal to new font and we probably copy this my equal
serve bold copy what did I copy there we go too easy so if only the bulb box selected
then font equals serif bold and then the size of 14 so now let’s go ahead and make another
else if for only if the italics is selected so copy we’re getting real lazy here but really
efficient how awesome is that italics or is it named italic box there we go it’s selected
then we want to change the font to font italic so now we only have one other option if it
runs through and sees that if bold is selected in italic is selected nope if both selected
note if italics is selected nope else this only else is going to occur if nothing is
selected so what do you want to do want to do the font and set it equal to new font and
I guess I won’t copy and paste it this time first its serif and the rest is font up plain
and of course we want to size 14s though so now well looks like we’re good to go and the
last thing we have to do now that we actually change that font we actually need to set the
font so in our text field we need to set font equal to that font that we just changed so
this pretty much says alright depending on what you selected I’m going to style the font
a certain way and then at the end want to test for all the styles it says alright I’m
pretty much just going to set it on the screen right now so now I have this from the last
tutorial which you guys can see it pretty much just makes a new window on the screen
puts a function on the window so you can actually close it size for that window and makes that
window visible so now if we run this and click OK we go ahead and we got this thing right
here and I promise you to change that size but this is good now you see when you click
Bowl with the sentence bolts when you click italics it italicizes to if you unclick bold
just as only italics and not bold and if you uncheck them both it’s back to normal now
let me give you quiet guys a real quick walk through one more time of how this works ah
take a deep breath you guys ready good we pretty much made three variables on screen
to hold the text field the bold box and the italic box in our constructor we set the title
in the layout nothing new we pretty much added text field bold box and italic box to the
screen and then we created a handler class to handle these events now again anytime you
click one of these boxes something called an item event occurs now this can be handled
by something called an item listener object so that’s why we needed to link this object
to this class then once we do that we can handle the events using a method called item
stay changed now this automatically runs well just like I told you before and what we did
pretty much is we pretty much had a variable called font to stylize the font right here
here here and here and then we pretty much once we found our style depending on what
was checked we set it to the screen and then we just ran our program made a window good
to go so that’s your quick tutorial on these are called state boxes because they maintain
a state like when you click them right here I’ll show you why when you click them they
stay like that so that’s called maintaining a state so that’s it for this story thank
you guys for watching and next tutorial we’ll be going over more gooeys and we’ll be eventually
making this box pretty effing sweet right now it doesn’t do a whole lot but you know
it will oh and another thing that if you follow my channel you know that I give away prizes
sometime I am waiting for prizes to come in the mail now and it will be the best giveaway
I had so far so just a little tip for you guys who actually stuck through this tutorial
and watched all nice little surprised don’t tell anyone else so trust me when I get my
prizes it should be like next week or something they’re going to be the best giveaways ever
so you know something to look forward to but for now thank you guys for watching don’t
forget to subscribe and I’ll see you next tutorial what is up guys welcome to your 66th
Java tutorial and in this tutorial we’re going to be making a GUI with radio buttons on it
and what a radio button is it’s kind of like a check box but the only difference is it
you can only have one radio button selected at a time so if you have 4 radio buttons and
they’re side to side if one selected and then you click another one the other one automatically
Dee selects and they actually got their name from the older radios I guess I don’t even
know if I was alive during this time but evidently the old radios when you press the one button
all the other buttons would pop out so you can only have one button select at a time
so that’s your real quick tutorial on what we’re doing and also a little tutorial on
old-fashioned automobiles so you know the Saiga 2 for one so let’s go ahead and start
making this right here we’re going to have let’s see like 10 variable variables or something
to start out the first variable we need is something called a J text field and this is
just the same one from less storoe and I’ll just name this TF like last time and this
is pretty much going to be the field that stores a text if you couldn’t tell and next
we’re going to have a private a font variable and we’re going to have four types of fun
we’re going to have plain font we’re going to have bold font and we’ll name that be F
best friend and we will have another font called italic font and you can’t write if
like this because if is a key word so you got to write ITF that might be confusing but
eh we’ll get through it and then lastly we’re going to have a font that’s both bold and
italic so I’m going to put bold italic font vif bit it’s pretty cool-looking variable
biff i got named more stuff biff next we’re going to have 4 radio buttons and these are
the buttons I was talking about so let’s go private and there’s J radio button just like
that and I’m going to name my first bun plain button and when you click this button it’s
going to give you that plain font right there so now let me copy this because I’m lazy and
make four more or excuse me three more next I’m going to have a bold button BB next I’m
going to have an italic button and I’m named IB and next I’m going to have a bold italic
button name bib so now this plane gives you plain file bold font italic font bold and
italic font when you click these buttons and the last variable we’re going to be using
in this tutorial it’s actually a group variable so let’s go ahead and write private button
group and you can name it anything you want I’m going to name my group for simplicity
and what this group is going to do this is pretty much going to establish a relationship
so that only one button can be selected at a time if we didn’t have them related they
know pretty much before separate buttons on your screen each acting independently we wanted
me each be part of a family so that way they can know when each other’s clicked in each
other’s on clicks or select it or deselect it if you prefer that so now enough for the
variables let’s go ahead and start making our constructor public GUI won’t take any
parameters and let’s go ahead and start making the body the first thing that we’re going
to want to add in our constructor is of course the title like always and I will name mine
the title pretty cool huh and the next thing I want is the layout so I’m going to put set
layout and of course in here since we don’t know anything else new new small flow layout
just like that looks good so now we got a title and a layout on our window what else
can we do to this well let’s go ahead and add that text field that I talked to you guys
about and I named it TF if you guys forgot and I’m going to set it equal to Nu J text
field and this field needs to be capitalized and for my parameters I’m going to first have
what’s in the text field so I’m pub lucky is awesome and hots that’s what I you know
that’s what girls usually say to me walking down the street but anyways and 25:4 sighs
and now we just need to add this text field to the screen because that we definitely want
that to show up so now we got a title a layout in the text field just chillin on our screen
so what else can we add well we probably want to put those buttons on there so I’m going
to take that PB which is that plain button I’m going to set it equal to nu J J radio
button just like that and the parameters for a button is first what do you want appear
to the right of the button I’m just going to have plain since it’s plain font and I’m
going to set this equal to true now hold on and let me H my ear Oh feels good oh I get
in there now the parameters it takes for true and false that are pretty much true is checked
and false is unchecked so if we’re stabbing a relationship we can only have one true at
a time so the first thing we want to do is set one of them to true and later on it’s
going to do automatically for us when you click it but for now let’s just go ahead and
copy this and the rest of them are going to be false by the way since we only want one
checked at a time because that’s kind of the concept of radio button the next bold button
is going to be equal to nu J radio button we’ll put this equal to bold and we’ll put
this equal to false now after let’s go ahead and copy this one make a life a little bit
easier so now we have two buttons created now let’s go ahead and what do we name this
other one italic button for IB purpose should named it a little more descriptive but and
we’ll name this italic and this will be the text chillin next to the button now set this
equal to false – and our less button is named bib bold and italic button so we’ll just have
like bold and italic sitting next to it so now that we created these four button objects
we can go ahead and add the screen using ad and PB this should make this so you can add
multiple ones at one time but I don’t think they do so add BB add IB and add what else
we got here BIP BIP BIP BIP there that’s enough that so now we pretty much created four buttons
and we actually added them to the screen so that they showed up now like I said before
the last variable we had it was this button group right here so that’s what we’re going
to be doing right here right now we’re going to be setting an object just called group
and we’re going to be setting equal to new button group like that and this doesn’t take
any parameters for a constructor and what this group is going to do is anytime you add
an element to the group it’s going to add it pretty much to the group pretty confusing
huh so let’s go ahead and group add and the first thing we’re going to want to add is
the PB which is the plain button so now this group has one button in it so let’s go ahead
and add another one group add dot b b now the group has two buttons in it think you
see where this is going group dot add I be sorry has be in there for us pretty cool and
group dot add and first one excuse me the last one bib so now our family has four buttons
in it and we were wondering all right how come we needed a group them we need to group
them so that they know when each other is checked and when each other is not checked
since we group these they automatically by default know that when one of these is checked
the rest of us has to turn off so that way only one button can be checked at a time it’s
pretty cool functionality that they you know built that in for us and we don’t have to
talk to each other for us so the last thing I’m probably going to be doing in this tutorial
is just setting the font which is up here P FBF ITF and bi F this is pretty much the
fonts that I’m going to set and I need these fonts to pass in later so the first thing
the plain font is going to happen when you click that plain button and it’s going to
be equal to new font and in your parameters for font first type Seraph and lastly font
the plane and give it like a size of 14 or something looks good and now let’s go ahead
and do this for the other one so there’s for me let me think plain font bold font italic
font so plain for bold font italic font bold attack bar so plain font bold font italic
font and vif right yup looks good to me so now this is going to be font dot bold for
the bold italic fonts going to be italic and the bold and italic fonts going to be fun
dot bold plus font daunt italic just like that so now we got our four fonts on the screen
well not yet but um that’s it for this tutorial so I’m going to catch up with next tutorial
don’t forget to watch it don’t forget to subscribe it’s going to be awesome it’s going to be
amazing so thank you guys for watching and I’ll see you next tutorial we were we will
finish this program what’s going on everyone welcome to 67th java tutorial and in this
tutorial we’re gonna be finishing this program demonstrating je radio buttons so where we
left off on the last tutorial we pretty much made four different kinds of fonts and now
what we need to do is pretty much take that text field and we need to set it equal to
a font by default and we just need to set it equal to a font by default so in the program
runs for the first time and knows what font to use so I’m gonna set equal to plain font
because I’m just a plain old guy you can set equal to different fun if you want but I ain’t
gonna so now what we need to do is pretty much create an add item listener for each
button so we can take that plain button first and add item listener just like that fun fun
fun fun there we go got clear on my throat and the parameter this add item listener takes
is gonna be this get out of my way new handler class and for the constructor we’re gonna
pass in the plain font now what happens is this an add item listener pretty much shows
there and waits for something to happen to that item which is in this case the plain
button now whenever it does happen what do we want the object because this is object
in here and what do we want it to do whoa for the handler class is gonna be handling
it or it’s pretty much the code that’s gonna happen if this button is clicked we need to
pass in plain font to the constructor and let me go ahead and add a comment so this
wait for event to happen and this what this doesn’t pass and font object to constructor
and we didn’t even create a class or constructor yet so this might be confusing but I spoke
constructor run see this this thing if I click it it’s not only a platform but it also is
a spellchecker so since I spoke constructor on it corrected it for me how cool is that
compiler and a spell checker double banger so now let’s go ahead and add this for well
the rest of them copy this and put that’s for a bold button italic button and bold and
italic button so bold 1c italic button is IB and bold and italic button of course we
need to change these to bold font and I said italic font was ITF and the bold and italic
font was that so now we pretty much got our constructor of our main class built now we
can go ahead and we’re giving this error message because handler class is not a class yet so
let’s change that right now let’s go ahead and make a handed request and we’re gonna
put this inside the other class so let’s go ahead and make private class hand or lower
a little alert class right there no my sound didn’t mess up I actually just said that implements
item listener and you guys know what implements means from the last tutorials so inside my
handler class the first thing I’m gonna want to do is create a variable since uh you know
we’re just gonna need one it’s gonna be a font variable and it set it equal to the name
of font because I mean makes sense right the next thing I’m going to want to do is create
that constructor that we used up here now as you can see that constructor takes a font
object as its argument so we got to make sure we have a foreign objects as argument when
it created it so let’s go ahead and make public and alert class and let’s go ahead and put
like font and just name it F or something so now plus I’m lucky TF so now in our constructor
for this and make sure yep looks right to me let’s go ahead and just add font and set
equal to F now let’s see what error I’m getting oh I must inherit the abstract method item
listener items state changed so since we use item listener it has a method in it cut item
state change that we need to use so let me add a comment to here and what this does is
the font object gets variable fun this is pretty much just changing the object we pass
in to the variable font so now that we implemented from item listener we need to use that method
called item state change so let’s go ahead and make a new method called public boy doesn’t
return anything item state changed and if I spelled that right we should be good so
now this argument takes the item event in which name it events and for this in the body
let’s just go ahead and have something like text font and we’ll set it equal to set font
for that font so now if I do this my error should go away but they’re not so I’m gonna
positive figure out what’s wrong okay guys I found my error and it was really embarrassing
actually he’s worth constructor of handler class up a handler class and I spelled it
wrong so you definitely need to put handler class and spoil your constructors right pretty
embarrassing if he asked me so you know not gonna let it happen again I promise so now
that we got all that changed let’s go ahead and well I’ll pretty much oh I had a comment
for this for ease of reading I will put sits the font to the font object that was passed
in looks good so well I’m gonna go ahead and run this then I’ll talk you guys through it
so I’m just gonna use my seen object from last oriole if you didn’t watch my less sorrow
then pause the video right now and copy that and I’m just gonna go ahead and run this and
hopefully it works so now we got Bucky is awesome as huh uh-huh thank you and it’s plain
by default like we said before and now you can see these radio buttons since they’re
part of a group then whenever we click one then the rest uncheck and that is because
they are part of a group and they’re able to see each other or know each other is doing
and that’s some built-in um methods that allow you to do that so that’s pretty cool right
there so let me talk you guys one last time through how we did this well let’s see let’s
just get to the hard stuff we made variables we added a we added all the stuff this screen
right here BAM here’s the confusing stuff aside from adding all the stuff to the screen
here’s what we did we pretty much need to add add item listener to each button so that
something can sit on those buttons and wait for it to be click or unclick now add item
listener this built-in method it takes this handler class object as a parameter so what
this is is pretty much saying alright we’re gonna be waiting for something happen and
as soon as it clicks then I’m gonna call this class right here and that’s the code that’s
going to happen when this event happens so now that we told it all right we want you
to wait for something to happen and when it happens do this we said all right what do
we want to do well we created a new handler class and the constructor for that class is
called an alert class of course and it takes a fog object so let’s go ahead and look at
that constructor right now the constructor all it does is it gets that font which was
plain font and sets it equal to the name font or the variable font and why do we need to
set it equal to this variable so we can use it later on to set the font so pretty much
we took that font set it equal to the word font and then in the item state change which
pretty much is the event that happens when it’s clicked it takes that font and sets it
equal to plain font bold fonts out font or plain and bold font or simply bold and italic
font so now that we have a constructor in our item state changed we’re good to go and
we were able to run the program so that’s your real quick tutorial of radio buttons
and the last thing that you guys don’t want to forget don’t forget to group your buttons
right here set equal to new button group objects in this group allows your buttons to be one
big family and allows them to see what each other is doing and this lets them know when
each other’s is selected or deselected so that’s that for this tutorial hope you guys
learned a little something not too much of course so thank you guys for watching don’t
forget subscribe don’t forget to check out all my contests and I will see you next time
what is going on guys welcome to your 68th draft tutorial and in this story I’m going
to tell you guys how to make something called J combo boxes now well Jake combo boxes it’s
pretty much just a drop down list but that’s what Java named it so you know they had to
be different so let’s go ahead and enough of the small talk let’s get started making
it and I just want to tell you guys what this combo box is going to do is it’s going to
give you a list of pictures to drop down in your drop down list and depending on what
picture you select is what’s going to appear on the screen so that’s a real quick overview
of the program so we need two variables one is going to be the J combo box which is going
to be the drop down list itself and I’m just going to name my box you can name your list
if you want but again I’m going to name em box and the next thing we need is the picture
to appear on the right hand side of it so I’m going to make it private J label in the
picture is our name J label in Java and I’m going to name my variable picture I mean why
not it’s nice and easy now the next thing we need to create is actually two arrays now
you see here I already have two images be paying in X topping and these are pretty much
just an image that says be an image that says X with a little graphics on it so we need
to create two arrays the first array is going to store the file name and the second array
is going to store the picture itself so let’s go ahead and put grab it static we don’t want
it to change string in remember this is going to store the path and the path is just a string
and I’m going to name it file a name and we’ll set it equal to B duck ping and make sure
you’re put in quotes since it’s a string so that’s the first element of the array and
the second one is X dot ping make sure I got PNG PNG in so now we have an array called
file name and it has two elements in it beat-up ping and x stopping simple enough now let’s
go ahead and add it or excuse me create a new array that is an icon array and we do
it like that and we’ll name this one picks and this is going to store the files there
themselves so let’s go ahead and as the first element what we need to do is put new image
icon and for the parameter of image icon put get class and it’s going to be this class
itself it’s going to select and get resource and the resource for this is going to be the
parameter it takes as a name and for the name we can write beat-up ping but let’s go ahead
and write file a name with the index of zero so our first element in this array is the
file name index of zero so let’s see one to make sure I got my parentheses there lot of
parentheses here yep that’s right so now let’s go ahead and just copy this so the first element
in this pix array is pretty much this B picture itself this is just a file name this is the
actual image so let’s go ahead and add the second array by pasting that in the second
element is file name one remember arrays start at zero and then the next one is 1 so now
we can go ahead and go to our next line so now we got two arrays one stores the file
names and one stores the pictures and we’re actually going to be using the file names
later so that’s why I just didn’t put the file names right here you’ll see why in a
little bit so now that we got all our variables in arrays we can go ahead and start building
the constructor like we always do so public my class is named GUI and let’s go ahead and
add a body of that constructor and the first thing we’re going to want to add as always
is the title and I’m just going to write the title not fancy and set layout su there we
go in the layout for this since we don’t learn layouts yet is new flow layout just like that
so now we have a title in a layout on our window what else can we do the first thing
we’re going to want to do is create that drop-down box with the file names is the list options
so I’m going to take that box variable that I created up here and set it equal to nu J
combo box if I can spell and the parameter it takes here is an array of options and since
we want our options to be beeping and X ping so the user knows what’s going on go ahead
and write file a name in here and what this will do is automatically put all of these
options in a list for us how cool is that so now let’s go ahead and get my cursor set
up and go the next line and what can we do after this well we have this box this drop-down
box just chilling here right now what we want to do is add some functionality to it and
we do this by adding adding an item listener so actually I’m going to do this in next tutorial
since it’s going to take a while I know I’m going to run out of time in this tutorial
but an overview right now we created a box we created variable for the picture that we
want to appear on the right side of the drop-down box we created an array of file names and
array of images of my two images we added a title set the layout for our window and
we added a box to the window then in the next tutorial we’re actually going to be adding
some events to this box so when you click one of the options something actually happens
but for now that’s it for this tutorial thank you guys for watching don’t forget to subscribe
and I’ll see you next door what is going on everyone welcome to your 69th java tutorial
I’ve been making a lot of Java tutorials I just noticed and in this tutorial I’m gonna
show you guys how to add some functionality to the box so what we need to do to add functionality
is add an item listener and one item listener does is pretty much this chills there and
waits for you to click something and when it clicks it it pretty much just well tells
it to do something so let’s go ahead and take that box because that’s what we want to add
an event to and we’ll go ahead and I’d add item listener there we go now as you know
an item listener usually takes an event handler object as its parameter well I’m gonna tell
you guys how to do something real quick here instead of having a new object like handler
and having it passed into the handler class what you can do is if you go ahead and there
we go just like that instead of having an object and creating a whole another outside
class somewhere else you can actually put something called an anonymous inner class
in here and what this does is it actually implements the item listener class so here’s
how you do that go ahead and type a new item listen or just like that and this is your
declaration for an anonymous class that implements item listener so instead of having like before
handler class implements item listener outside and we have to make a whole new class what
we can do is just go ahead and stick a class in here and pass it in for the parameter as
add item listener and we bypass that entire step of having to create a whole new separate
class so again since we named a none anonymous class that implements item listener we need
to use that method and that’s called item state changed as you can see right there so
what this class has to have in there is only one method that’s know let’s go ahead and
create it right now item listener has let’s go ahead and make it public void item state
change I gotta make sure I spell that right and did I oh yeah nice now what we have to
do is of course it takes in item event event just like that and as our body for this we
just go ahead and write whatever we want to happen when we selecting one of the options
and here’s how you can do that go ahead and make a if statement in this if statement determines
what option you selected so if the events get state change this pretty much if you click
a button we want to set it equal to or excuse me we want to test if it’s equal to item event
dot selected so what this pretty much means all right did you select a button is equal
to what was this pretty much means what was selected just a nutshell so what will select
it first of all whatever you select do we want to take that picture and remember this
is just the picture that appears on your screen we want to set icon which pretty much means
change the image to and the parameter says what icon do you want changed to well we have
an array called pix and what we have the thing is we have two elements or two images in this
one so what when do we select well go ahead and type box dot get selected index with empty
parameters just like that make sure typed everything right parenthesis bam bam now make
sure the method gets state change is undefined type and oh here we go hold on a second all
right guys in all of my excitedness I did another stupid ear I actually put get state
change instead of changed quite embarrassing make sure you type that right but now pretty
much that’s all we needed to do so what this does is it makes anonymous inner class and
this is the class it’s and in this class the only thing we needed to do is since the implement
and item listener we needed to add an item state changed method since that was the only
method in item listener and then we pretty much just said our right while item did you
select or what option did you select in the drop-down list and change the picture to that
icon or item so now we can go ahead and get out of add item listener and we can pretty
much just add all this this screen so add that box to the screen and remember that box
is just the drop-down box and now we want to take that picture and add it to the screen
but by default let’s go ahead instead of equal to nu J label and we’ll do pix 0 and this
pretty much just gives a default value so you know something appears before you choose
any options and lastly let’s just go ahead and add that picture to the screen just like
that and we shouldn’t get any air should it and now let’s go ahead and just run this and
I’ll show you guys what we get by default again like I said we have B on the screen
which is at the end X is 0 then when we select X our picture changes the X we can go ahead
and select B X we can do this all day if we want really but no time for that we need to
overview our program so what we did is pretty much let me get the good stuff we made a box
variable a picture variable just a hold box and picture later on we made an array of file
names and we made an array of images named pics and then we went and go ahead and our
constructor which is pretty much making the window we had a title editor layout we set
that box equal to new jcombobox and it took the file names is the options so again if
I go ahead and run this this these options right here are the default for file name so
that’s why that was able to run and the only confusing part which we did new is this instead
of having a new object in a new class we just went ahead and stuck the handle class inside
the add item listener and that was actually an anonymous inner class and what we needed
to do is we needed to overwrite this method item state changed because that was the only
method in item listener and we overrode it with a nice little function right here and
then we went had to added the box at a screen then we went ahead and added the picture this
screen and just gave a default setting and we were good to go so again here is our awesome
little program right here flawless no bugs no anything so that’s all you get for this
tutorial thank you guys for watching in the next tutorial we’re gonna be going over something
else cool you can do with gooeys and well that’s it so again thank you guys for watching
don’t forget to subscribe and I will see you next door what’s going on guys welcome to
your 770 a–the there we go Geoff tutorial and this is ro we’re going to be going over
something called Jay list now what Jay lists is is it’s pretty much a list for your GUI
and when you click on one of the options we can make an event happen such as in this case
switching the background color so let’s go ahead and get started if you can’t tell I
imported one more thing here so make sure you have all of your imports right here if
you need them pause the screen but you’re probably don’t so I’m just going to go ahead
and minimize those right there and now we’re good to go the first thing we’re going to
need to do is make a variable for that Jay list so let’s go ahead and make private Jay
list because that’s what type it is I’m going to name my list for simplicity now after this
what program we’re going to be making is we’re going to have a list of colors and when you
click on one of those colors it changes the background so we’re going to have two arrays
one for the color name and one for the actual colors himself that the computer can recognize
so one that we can recognize and one the computer can recognize so let’s go ahead and make our
first array just the color names that we can recognize so it’s going to be private static
string it’s just going to be the names of the colors and just name it color names and
we’ll set it equal to let’s go have a color like black blue red and white I have four
colors inner lists can have more if you want but I’m just going to have these basic ones
and make sure to put them all in quotation marks like this and then and your line with
a semicolon BAM you’re good to go so I have four color names in our first array called
color names now the second thing I want to do is build an array of colors that the computer
can understand so go ahead grab it static again I’m going to name this array color or
excuse me it’s going to be of the color type and I’m going to name it colors and in this
list we’re going to put the colors in the way that Java sees them and that’s this color
dot black all in cat so that’s how Java sees colors or recognizes them it’s from the color
class and then you write the name of the color all in caps and our next one’s blue so color
the blue all in caps and our next one’s red so color dot thread all the caps and color
the white so now we should be good to go looks like America in any airs and now let’s go
ahead and we have our three variables pretty much list coloring names and colors we can
go ahead and build our constructor or window so go ahead and go to your instructor and
it’s not going to take any arguments just go ahead and do some housekeeping stuff add
the title and where you at curse oh got the hiccups and embarrassing and next thing you
want to do is set the layout and just going to set this to normal flow layout by putting
new flow layout I wonder why they capitalized the F in that one pretty weird and don’t forget
your empty parameters so now I have a title in the layout now we can go ahead and start
messing with our list the first thing we want to do with our list variable is actually create
something and what we need to do is create a new j list and the parameter J list takes
is an array of what you want the person to see and we want the person see the color names
is the options so let’s go ahead and just write color names in here um you don’t need
it in like quotation marks or anything like that so now we have a list and it pretty much
is just a list of color names what we want to do now is set how many rows are pretty
much the height of the list so go ahead and take that list and put set visible Arial row
count right there to easy and what this is is how many options the user can see by default
now if you put like they can only see four but there’s like ten items in the list a little
scroll bar is going to appear on the right but since we only have four and we put four
then it should fit just perfect um the next thing you want to do is go list set o it’s
called selection mode there we go right there set selection mode and for the perimeter it
takes is this some lists allow you to select one thing or another thing and some lists
allow you to select multiple items the one we want to use is we only want to be able
to have a single selection at a time so we’re going to have as a parameter list selection
model dot single underscore selection just like this and now instead of like cooking
control and selecting many things or shift the user can only select one thing in the
ERR list at the time so now the last thing we need to do since we got our list all made
is just add it to the window or well yeah that’s all we need to add it to the window
so add new j scroll pane and of course we want to add our list to here and now we added
our list to the window pretty much so in the next tutorial we’re going to be adding some
functionality to this list and it’s a little different than the other tutorials I’m only
teaching you something even newer and easier in the next tutorial but for now thank you
guys for watching don’t forget to subscribe and don’t forget to check out the next tutorial
so I’ll see you then what is going on everyone hey guys doing welcome to 70 first job tutorial
and in this tutorial we’re gonna be adding some functionality to this list we just made
on screen so let’s go ahead and inside her constructor so let’s go ahead down a couple
lines and what we want to do is add a selection listener to this list so what we want to do
is put list dot add list well look at that already has it for us add list selection listener
and then go ahead delete this because we’re not gonna need it and we’re gonna make just
like last sort of you saw another anonymous inner class so go ahead and in your first
line of the parameters for add list selection listener what we wanted to do is make a new
anonymous class and remember this is just an easier way of handing it handling so put
new list and then see you listen selection listener just like that it’s gonna take no
parameters and we should say must implement yep must implement method value changed so
this is pretty much says whatever classroom aid implements list selection listener it’s
just a easier way of bypassing it the thing is we need to make a method in here called
value changed that’s what it’s telling us right now so in like orders to fulfill our
duties of implementing it so let’s go ahead and make public void value changed in all
this is pretty much what you need every time you make a J list so let’s go ahead and fir
the parameters for this is list selection event and go ahead and type event and now
we can go ahead and start doing the stuff that we want to do so pretty much aside from
this all of this stuff is pretty much built in Java and you need this every time it’s
none of your own custom stuff so it’s just the easier way of adding some event handlers
to your program so now that we got all this housekeeping stuff done let’s get into the
good stuff what do we want to do when a user clicks one of the colors well what we do want
to do in people language is select that color and change the background to that color so
actually there’s three different layers on our window the first there’s a background
there’s a content pane and there’s something called I think it’s called a glass pane now
the content pane is on top of the background so they have a set up a really weird you need
to actually access the background through the content pane in order to change background
so the first thing you need to do is get content pane like that and the second thing you need
to do is finally we get to our background so let’s go ahead and set background just
like that and I spout that around background that’s a little bit better and there we go
my hair goes away and so what do we want to set the background to well in our parameters
for here let me just end this statement and our parameters for here we want to set it
to one of these colors from the color list color black color blue color red color right
so the first thing we’re gonna nuke you need to do is add color and empty square brackets
and now what we want to appear in here is one of the numbers one through four so how
can we get the numbers one through four depending on what they selected remember in our list
was the array or excuse me was the array color names and our list was named list so let’s
go ahead and put list dot get selected index so it’s automatically gonna know whenever
we do not want to put that there let’s see so it’s automatically gonna know that in our
list that we just created and why am I getting a line under color because it actually colors
there we go so when whenever it clicks our list in by it I mean we it’s automatically
gonna know if we click the first second third or fourth item our list it’s gonna get that
number and it’s gonna say alright if you click the third item in our list I’m gonna pass
three in four here so color is three equals let’s see colors zero actually one two three
so it’s gonna be red so that is how it happens like that and remember to set the background
you need to get the content pane and get set background I don’t know why they did it this
way instead of just you know set the background but they did it this way and don’t forget
there’s actually three layers the content pane background and I think it’s called like
a glass pane or something something weird so that’s that for this story and let’s actually
run this program and see if it works so I see by default it’s nothing because we didn’t
send it to default value now when you click black blue white red blue red black white
and any order then that’s pretty much just what happens so one more time and let me walk
you guys through that the first thing we did is import all our stuff make sure you have
those it’s key trust me and let’s see let’s get to the important stuff we made a list
which is a variable further list we made the color names which is what we saw on the screen
and we had a correspondent to the colors so that Java can understand it using the special
colored black next we made a constructor with a titled layout yada yada yada we made a list
and we set it equal to J list color names which were the options that the user can see
set the visible row count which was four options by default then we made a single selection
so you can only select one at a time and we made a J scroll pane which gave us the scroll
window if necessary next we added all this stuff which is pretty much the default stuff
you have to add in Java and finally we added this little line right here we went to the
content pane so we could get to the background and then depending on what index they clicked
we corresponding it to list of colors that we made up here so one is black twos blue
threes red four is white so that is how we did that and that’s how we made an awesome
little program and look at this how awesome is that it seriously red white and blue didn’t
even notice it black where does that come in but anyways thank you guys for watching
don’t forget subscribe and I will see you next tutorial what is going on guys welcome
to your 72nd Java tutorial and in this story I’m going to be teaching guys had build a
multiple selection list and in the last tutorial you guys learn how to build a list with a
single selection or in other words you can only select one item at a time but in this
tutorial I’m going to be building a program where there’s a list on the left where the
bunch of items and there’s a button in the middle and when you select a bunch of items
on the left and click the button it moves it to the right so it’s going to be a pretty
cool tutorial and actually the cool thing about this tutorial is all the hard stuff
we need to do is already built into Java so I just need to teach you the methods so let’s
go ahead and get started make sure you have all your imports right there I’m going to
go ahead and minimize that and now let’s go ahead and start making some variables we need
to lists and a button to start out so private Jay list in the first list I’m just going
to name left list since this is going to be on the left hand side and I’m going to make
another one identical to this but I’m going to change can’t keep talking I’m going to
name this right list since this is the list that’s going to be on the right hand side
so now we’ve made two variables for left list and right list and they’re both two J lists
so now let’s go ahead and just make a button private J button and I’m just going to name
my move button because that’s what it’s going to do it’s going to move this stuff from the
left to the right it’s actually going to copy it but you know what’s the difference now
of course we need an array or pretty much items to go in our list and I’m just going
to have it private static and I’m going to have a string because you know she’s going
to be names and I’m going to have foods you can have anything you want it really doesn’t
matter but foods sounds something I can it’ll be interesting so let’s go ahead and type
the foods I like which is of course bacon and let’s see what else wings had some last
night they’re amazing bone sucking sauce look it up ham and let’s get like two more beef
I don’t really really like beef all that much but I like the name of beef and that’s the
important thing and the last thing of course more bacon and let’s go ahead and end this
so now we have an array called food and actually name that foods because I mean it’s foods
bacon wings ham beef and more bacon now make sure I got that and so now we have the four
variables we need for this tutorial left list right list the button in the array so now
let’s go ahead and start well I guess we can go ahead and start building our constructor
so public GUI of course it doesn’t take any arguments and let’s go ahead and add a title
first called super just name it title and make a layout next so set layout and of course
nothing new here we’re going to get new flow layout with empty parameters and now let’s
go ahead and start editing that list on the left the first thing we need to do is populate
it with the foods so it’s new jlist and any time you use a j list it takes the argument
of an array or in other words what items do you want to put in it so we want to put those
foods in it so let’s go ahead and put foods in it BAM a little too easy the next thing
we’re going to want to do to left list is if I spell it right is add the visible row
count so set visible row count and make sure BAM look at that how easy is that so how many
of these items do you want to see by default and I want to see three items by default so
now that our list is five items but we can only see three what we need to do is add something
called a scroll pane that we’re going to add later on right now left list dot set selection
mode right there too lazy to type it and go ahead and and this statement and our selection
mode unlike before it’s going to be list selection model not Mosel model dot right there multiple
selection and what this means is unlike last time where you can only select them one thing
at a time with multiple interval selection using your ctrl + Shift keys on your keyboard
you can select multiple items at a time using this so now the last thing that we need to
do to our arm left list is add it to the screen and also like I just told you guys before
we need to add a new J scroll pane right here and what this allows you to do if we add the
left list eventually is it allows you to have a list bigger than default viewing and it
pretty much just put a scrollbar on the list that’s what I’m trying to say it pretty much
puts a scrollbar on your list so now we did our left list so now all we need to do now
is make our move button and write lists so go ahead and click move button and set these
equal to nu J button and make sure you have a space in between there and the parameters
frist is the text you want to appear on the button so I’m just going to have move and
a little arrow just like that so you know that we’re moving from the left to the right
so now we can go ahead and add action listen or listener of other words functionality to
this move button so move button dot add action listener awesome and of course this is going
to have an inner class because it’s a lot easier so inside your add action listener
parameter just go ahead and make a whole new class called new not boo new action listener
just like that and this class of course doesn’t take any parameters and inside your new action
listener inner class we want to have one method and if you can see by our air it’s called
action performed so let’s go ahead and add public void action performed make sure I spelled
it right PR fo r m e D looks good and as your parameters for this just right action event
event BAM this is a little too easy that’s the only problem with it now we can finally
get to the good stuff of what we want to do again this is all default stuff that you need
that’s how did they just made the program but now we get the custom stuff what we want
to actually do well the first thing we want to do when we click the move button is build
our write list we’ve already built that left list but the right list depends on what we
select in left list so go ahead and type write list da and the first thing we need to do
is set the list data or set the things we want in the list so go ahead and set list
data and what this does is it takes an array is its argument just like let’s see just like
J list took an array as its argument set list that is also going to take an array that’s
its argument to set the list data so how do we get an array of selected values from a
left list well this is another cool thing just go ahead and type the left list dot get
selected values right there how awesome is that get selected values and what left less
dot gets selected values those is whenever you select stuff on the left-hand side of
your screen or in the left list it makes an array of those selected values and that array
is going to be passed into set list data and essentially is going to create a list on the
right-hand side depending on what you selected on the left hand side how cool is that we
don’t have to make a new method for setlist data we don’t have to make a new method for
get selected values everything’s already built in method so that is you know it’s just awesome
so now that we made this button and we added some functionality to it let’s go ahead and
do one last thing and of course we need to add it to the screen so let’s just go ahead
and click add move button and now our move button is added to the screen so in the next
tutorial we’re going to be finishing up this program and actually on building a write list
and you’ll see what I mean in the next tutorial so for now I guess I’ll see you next time
thank you guys for watching don’t forget to subscribe and I will see you soon what is
going on guys welcome to 73rd Java tutorial and in this tutorial we’re going to be finishing
up our program and actually running it so in the last story we created a list on the
Left we created the move button we added some functionality to it so now we go ahead and
only thing we have to do is create the list on the right so let’s go ahead and make right
list and just go ahead and like set it equal to nu J list and we don’t need any parameters
for it because by default we want nothing in it so that’s why I don’t need any parameters
for it right now you can if you want but I mean it’ll be kind of useful and hold on let
me H my ear feels good right in there Oh disgusting so now what we need to do is since we have
nothing in our list by default then it’s not even gonna appear on the screen by default
since I mean it doesn’t have anything in it so what we need to do is set a default height
and width for it pretty much so let’s go ahead and see what are we put up here for 3 ok what
we need to do is first take that write list and to make sure it appears on the screen
by default what we need to do first is get out of my way set visible row count and I’m
gonna set this equal to 3 because our other one is set to 3 n I just want some consistency
so next I’m gonna take that write list and we need to set fixed cell height and width
so set fixed so let’s do with first I mean only makes sense it will set a width of like
a hundred and do the same thing for height right list set fixed crap my default thing
height and we’ll set this equal to like 15 or something like that and this should be
enough to hold her values if it’s not we’ll go back and tweak a little bit but oh well
and the last thing we have to do aside from this is take that right list and we need to
set the selection mode like before it so set selection probably can copy this from up there
but too lazy to set the selection mode make sure to enter right get selection mode and
what this is into list selection model dot and we’re gonna write Wow how convenient is
that multiple interval selection so then once I type a write list and type this right what
this is going to do is allow you to select the multiple items from the right-hand side
and I know you guys can’t see that multiple interval selection so just like that now that
we have our right list made the only thing we need to do is add it to the screen so let’s
go ahead and add new j scroll pane so we want a scroll ball urn this one to write list so
now we have everything added to our screen and our program is basically built right here
so let’s go ahead and in our main I already have this stuff from the last Oriels let’s
go ahead and run this and see what we got well I resize my window a little weird but
we can always change that by setting the size right here but I’m too lazy for now so as
you can see the title is tighter title and now unlike before where we can select single
things if I hold down the shift key on my keyboard look at this click and now I get
a multiple selection or if I hold down ctrl on my keyboard I get that selection where
you can select like every other one or if you want to deselect something just click
it again and now if you move it you get bacon more bacon or if we want bacon in ham I’m
going to click bacon hold down shift click ham and move and we get bacon wings in ham
and of course following everything let’s go ahead and just select that move and now we
got everything right there so that is pretty much the program of using a multiple interval
selection or or in other words multiple selection lists and one quick time how this program
works we’ve pretty much made variables right here in an array we took that array and passed
it into left list so left list will have something to display we set the visible row count we
made it so you can select multiple things and we also made a scroll bar on the left
list then we got to the move button we did all this default stuff on he also did this
cool stuff setlist data of the right list automatically depending on what you select
in the left list that’s why whenever we create click move it first looked what we selected
in the left list and depending on what we selected that’s what I put in the right list
so this is how you do that using setlist data in the get selected values method we added
that button to the screen and then what we did is we made a new write list that was empty
by default and since it was empty by default it wouldn’t display if we didn’t give it a
height in width and now we made that list so you could select multiple things in it
even though you didn’t really need to and last but not least we added the right to the
screen so everything was added to the screen and it was good to go and it was good to run
so that is our final program using multiple selection lists I hope you guys enjoyed it
I got the hiccups now so thank you guys for watching don’t forget to subscribe and I will
see you next tutorial what is going on everyone welcome to your 74th Java tutorial and in
this tutorial we’re going to be going over something called Mouse event handling now
we already went over stuff like Liz then what happens or what we want the program to do
if the user clicks a button or something but we didn’t go over what they would do if they
like press the mouse or click it or if they drag the mouse and this program we can respond
to Mouse events that the user does just like I just talked about like they click it or
if they move it and stuff like that so let’s go ahead and get started and then well once
I’m done with this program you’re understand how to respond to users Mouse events so the
first thing we need to do is import a bunch of stuff as you can see I got rid of everything
for my other tutorial so let’s go ahead and import java.awt dot let’s go ahead and just
import all of them and this is going to import stuff like colors border layouts and well
stuff like that next we want to import java.awt event in all of those and these are pretty
much our Mouse events and lastly what we want to import is import Java X dot swing dot all
of those so now we got all the imports we need I believe if not we’ll import them later
but I’m pretty sure that’s all so after this let’s just go ahead and get rid of that ticker
and make two variables we’re going to have two things in our window so we’re going to
have a private variable jpanel and actually that needs to be jpanel and just name this
like mouse there we go I’ll get it eventually Mouse panel and this is gonna pretty much
be the area where you can like click and move your cursor around so it’s pretty much just
going to be a big white box and we’re going to have another variable to hold another piece
of our window and that’s J label and just set this equal to like status bar so here’s
what our window is going to look our window is going to look like it’s going to have a
big empty space and that’s going to be the called the Mouse panel and this is where we
can test out all our mouse events like click a drag release and we’re going to have a status
bar at the bottom and when we click we want the status bar to say you clicked when we
drag we want to say have the status bar say you are dragging but you know we got program
all that so let’s go ahead and get to it so after we got our two variables we can go ahead
and make our constructor which pretty much going to construct our window so name it public
whatever you name your class I named my GUI doesn’t take any parameters because its constructor
I mean I mean come on seriously we’re not going to pass any constructors or parameters
into it and then we did super to of course change the title of it because that is the
constructor of the superclass jframe changes the title um in other words just put super
and put title whatever you want now we pretty much got a window with a title bar on it not
very exciting so let’s go ahead and change that mouse panel and actually make it something
and we will set this equal to nu J panel so now we actually set it equal to something
so we can use it now so now let’s do something else with it something a little more exciting
take that mouse panel and let’s go ahead and set the background color using the built in
method set back around and you put note the output color and is the arguments it takes
a color so go ahead put color white so we’re going to put this out white default but don’t
worry we’re going to be changing it to something more exciting later on and the last thing
we need to do is of course add this to the screen so go ahead and add mouse panel but
we don’t want to do that if you can notice we didn’t have a flow layout like we did last
time so for this layout go ahead and put boarder layout dot Center and this is just going to
make it appear in the center of the screen and fill up all the empty space and we’ll
be going over layouts later on so you prize you guys probably don’t know what this means
yet but trust me you will in a little bit so now we have on our window which is this
we have a title which is the title bar and we have pretty much a background not very
exciting so let’s go ahead and add that status bar we talked about right here so go ahead
and type in status bar and we will set this I spell that right all these underlines it
like I spelled it wrong or something and we will set this equal to Nu J label remember
don’t get this confused J panel J label your status bar is the J label and just set it
to um and just put default because that’s what’s going to happen by default so now we
have a status bar that says default by default how clever is that so now let’s just go ahead
and add it to the screen what we’re doing we’ll be changing it later with the Mouse
events but for now we just want to add it to the screen get done with status bar and
for this order layout south and this is means for real simply it’s going to appear at the
bottom of the screen so it’s a little more than that when you learned about layouts but
for now trust me just means meal screen fill up on this all the empty space appear at the
bottom the screen simple enough and if you couldn’t guess it has north south east west
and center so anyways let’s talk about something a little more useful in order to use our mouse
events like mouseclicked mousepressed we need to make a new handling class to handle these
events so I’m going to make um I’m going to make a class declaration right now even though
we didn’t make the class yet so in the future we’re going to make a cat class called handler
class and I’m going to make my object called like handler something something easy and
of course we’re going to set it equal to new handler class I’ll make sure I don’t type
anything around there so now there we go make sure they’re spelled the same that’s how I
check if you’re using eclipse and if you like click one thing it will highlight everything
else yeah I mean just a neat little tip because if you’re like all right why am I getting
air in here and not here just click it once oh it’s not how I there’s spell different
BAM so anyways what we want to do is we’re going to add two listeners because we’re going
to be implementing from two different classes there are two different types of ways or there
are pretty much two different types of mouse events the first set of mouse events is like
anything that you can do when the mouse is still and these include press clicked release
and there are two other ones that are kind of funky called entered and exit which is
enter the space and exit the space but the next class we’re going to implement from is
what you can do while the mouse is moving and you can of course move the mouse or if
you hold down the mouse is called dragging the mouse so let’s go ahead and add two listeners
or a hat right here right here I meant sound like a what’s that guy from politics yeah
whatever he is that’s why I just sounded like so Mouse panel dot add Mouse listener how
easy is that handler so of course add Mouse listener weights and it takes an object as
its parameter so that’s why we passed in handler and do it again Mouse panelled add always
called Mouse motion listener and of course this takes handler too so now we’re getting
error here because we didn’t build the class yet which we’re going to do in the next tutorial
but now let me go over this real quick we imported everything we need because we needed
some stuff we extended J frame which allowed us to built windows we made two things in
our windows a panel and status bar then we set title of our window and then then we pretty
much just set the color or the background added it to the window we made a status bar
added that to the window at the bottom and then we made this new handler class with the
object handler and we need to make an object because these two built-in methods that wait
for Mouse events they take an object as their parameters so in the next tutorial we’re actually
going to be going over some of these Mouse events such as what happens when you click
the mouse and we’re going to be adding some functionality to it anyway if we have time
we’ll probably run it but we might not so thank you guys for watching now cannot wait
to build this next class in the next tutorial so again thanks you thank you don’t forget
to subscribe and I’ll see you next time what is going on guys welcome to your 75th job
tutorial and in this tutorial we’re gonna be going over how to handle those Mouse events
so in the first tutorial we pretty much we built a window so let’s go ahead and go outside
our constructor right here and we want to make a new class and let’s go ahead and make
it make it private class and you got to name it whatever you name it up here so I named
mine handler class and then what we want to do is implement from two other classes so
implements Mouse listener and it also implements Mouse motion listener so hopefully those errors
go away and they did so now what implement means is we have to use every method that
was in the class Mouse listener and there are five methods in this and Mouse motion
listener and there are two methods in this so what Java did is they put methods inside
Mouse listener and Mouse motion listener to automatically detect Mouse events so whenever
you move your mouse it’s gonna be registered in an object called an event so let’s go ahead
and I’ll just start building these methods and you’ll see exactly what happens so the
first methods we need to implement are those five methods for mouse listener and these
are mouse press mouseclicked Mouse released Mouse entered and mouse exited and I’m gonna
tell you guys what these do when I go through them but for now let’s go ahead and build
our third one first one so public void Mouse clicked and what this does it is whenever
you click down the mouse and what this means and I know you guys forever saying are AI
know what click means when you press and release the mouse really click really quick Wow embarrassing
that is a click now a mouse press and a mouse release are two different things so you know
maybe guys then no equipment after all but this is what Java defines a click as so and
all these parameters are gonna take something called this Mouse event event so you might
as well just go ahead and copy that and copy that like that because we’re going to be using
it a lot later on so now whatever we type in here is finally what we want to happen
when the mouse gets clicked so let’s go ahead and take that status bar and we want to change
the text on it so status bar dot set text and what do we wanted to set the text equal
to well let’s just go ahead and put let’s put string format and in our format parameters
it takes two parameters itself and the first one is clicked at percent D comma percent
D so it’s going to say clicked at two coordinates in Java also has two coordinates based on
this event right here why do you have this event because it registers the event like
when you click it decides where it clicked and you can get to this the locations by clicking
event get X and also but guys probably can’t see this it’s a little better and also event
dot get Y with empty parameters so now whenever you click this you get the x-coordinate in
the y-coordinate of where the event happened and you guys can see this later on but for
now let’s go to the next event the next one’s will be a lot easier I just wanted to demonstrate
that you can get the x-coordinate and get the y-coordinate and one of them but and the
rest of the methods I’m gonna make them real simple so we made something that happens when
the mouse is clicked but we need to implement the rest of the functionality and the second
one that we need to implement is public void Mouse released and this is what happens when
you release that mouse button so actually let’s go the second one is Mouse pressed that
people usually do so let’s go ahead and mouse pressed is what happens when you press down
that mouse button so go ahead and throw your mouse event event in there and for the body
let’s just go ahead and put something like status bar set text this is gonna change the
text on our status bar to like you pressed down the mouse so now this is what happens
that or excuse me the status bar is going to pop up this text whenever we press down
the mouse and now we can get the public void Mouse released and this is the event of when
the mouse releases or after you press it down you let go of the button so this is all easier
see with our program actually so let’s just go ahead and copy this now because we are
too lazy and it’s going to say mouse release so you release the button so now we have three
methods that we implement it what happens when you click the mouse what happens when
you press and release the mouse and believe it or not these are actually three separate
things I know you think press and release is the same thing as clicking but trust me
to Java it isn’t so now in this class there are two other methods that we need to implement
public void Mouse entered and what this is gonna take is of course our mouse event event
first of all I can’t forget that taste that baby right there that’s what I’m talking about
and what Mouse entered means is this is the event when the mouse enters the area in our
area is of course um where are you mouse panel right here so this is what’s going to happen
whenever the mouse enters the mouse panel so remember up here we put it at white by
default so now let’s go ahead and change that actually the first thing we can do is click
status bar set the text to something like you know you enter the area not bad and now
let’s go ahead and change the color of our mouse panel so mouse panel dot sets background
not bad ground set background and what do we want to set it to when the mouse enters
um just put something noticeable colored thread or something like that I mean it’s pretty
noticeable come on so of course you’re wondering all right you have a mouse entered method
something tells me that you’re probably going to have a mouse exited method as well well
if you guess that then you would be correct so public void Mouse exited make sure I didn’t
spell excited I do that sometimes because I myself get excited about this method sometimes
so you know it happens so go ahead and type mouse event event nothing new so what this
happens whenever the mouse exits the window pretty much in essence so the first thing
we want to do is cyst status bar set text and put the mouse has left the window BAM
pretty much make sure you spell the wrong make sure you put he instead because I’m too
lazy to fix it although but easily could just fix it right there anyways enough of that
so now let’s take that mouse panel and whenever the mouse is in the window it’s gonna be read
so whenever we exit the window it let’s go ahead and set set background we’ll just set
this to I guess white again I mean why not make sure we don’t got any errors and we did
it so all of these five methods right here these are the mouse listener events but again
we implemented for mouse listener and mouse motion listener lucky for us Mouse listener
has five methods which I already did and Mouse motion listener which is on the that the methods
our mouse dragged and mouse moved it only has two so this one’s gonna be a lot easier
so in the next tutorial we’re gonna finish up building this program and all we have to
do is implement these two methods Mouse motion listener which are like I said dragged and
move and once we do that we can finally run our program and see what it does and it’s
gonna be awesome it’s gonna be amazing but for now thank you guys for sticking with me
thank you for learning Java with me don’t forget to subscribe to my channel and I will
see you next tutorial what is going on everyone welcome to your 76th Java tutorial and in
this story we’re going to be finishing up that program that lets us do Mouse events
and well that’s pretty much it so in case you can’t tell right here we implemented from
two different interfaces which are pretty much just a class in essence the mouse listener
and we did the five methods necessary for that but we implemented from this other one
to Mouse motion listener and these are pretty much like you can see the motions of the mouse
so when you move the mouse like this or click and hold down and drag that’s what registers
these events so these are pretty useful for a good drawing programs and stuff like that
so let’s go ahead and implement the methods right now so public I’m like a little comment
um these are mouse motion events so not just the typical mouse arm or they call a mouse
listener or whatever so the first method we need to make is called mouse drag so public
avoid Mouse dragged I always heard it was drugged like Dig Dug Drake dragged anyways
just talk to myself here so let’s go ahead and put mouse event events nothing new here
and for the body what do we want to do when they drag the mouse well let’s go ahead and
there’s nothing really we can do except change the status bar dot set text and we’ll set
it equal to something like put that back come on Hoss you are dragging the mouse how original
is that I know it’s most creative thing I can’t come up with but hey I’m not that creative
that’s what my therapist told me so I’m just going to go with that so after that what we
need to do is have mouse move and what mouse move does is called when you move the mouse
without clicking any buttons just like I’m moving the right here and I’m not click any
buttons so mouse drag is when you hold down the button but public void amounts moved is
not holding down any buttons so let’s go ahead to Mouse event event and in our body what
do you want to put status bar dot set text and go ahead and just put something like you
move the mouse so now we got MOU SEO of course that’s how you spell Mouse so now we got all
of our methods that we needed to implement since we implemented from Mouse listener and
Mouse motion listener so now we can go ahead and run this program and I’ve down Lee doesn’t
see one of these things that’s boater on Haan DL er CLA SSH Andi oh there we go make sure
your capitalisation does matter it’s case sensitive in Java as you just saw so now let’s
go ahead and run this program right here and I’ll show you guys what happens if we don’t
got any errors it’ll pop up trust me so here is our window by default it has the title
bar at the top and here’s the status bar down here and here’s our mouse panel and so the
first thing we see is well let me go through each of these methods look at the status bar
down here I’m going to press down or hold down the mouse button and says you press down
the mouse button now when I release it it says I clicked at that coordinate because
when you press down your release it real quick it’s a click server saying all right if I
press down and release it that’s a click how do I get this to the release method well if
you click it and drag it and let it go that’s the one that says you release the button so
if you click down and release in the same spot it’s a click if you click down and drag
it and release it it says you release the button so now what do we have we have mousepressed
mouseclicked mouse released we also have mouse entered as you can see as I’m entering it
it’s changing a red is I’m exiting it the mouse has left the window it’s changing white
and lastly I have you move the mouse and if I hold down my button look I’m clicking down
the button and dragging it says you are dragging the mouse so now let me talk through each
of these methods you guys should know what all this means how to create the window by
now if you’ve been watching my tutorials and let me talk through each one of these remember
well I might as well just run that again so I can bring it up bring it right there so
remember when it said mouse clicked it set the text equal to the two coordinates % d
% D which was event get X and get Y and I know you guys can’t see get Y but trust me
so look at this click at 10/10 65 click that 30 46 so that is pretty much what it means
in for your information the X is left to right and the Y is top to bottom it starts 0-0 right
here and it increases the most right here it look 279 141 so that is what click thus
the mouse pressed is pretty much taking it right here and when you press it down that’s
why we were able to get this text you press down the mouse mouse released let me make
sure I can’t move my mouse you release the button so that’s why we’re able when we let
go of our mouse button and of course when we enter the area it not only says you enter
the area for a short bit of time but also changes the color to red look at this non
anandhan oh I entered I’m not I didn’t come in yet oh I just entered again it’s red so
now what else did we do exit is white it’s the same thing and the last one is dragged
which is holding your mouse button down that way we were able to set the status bar too
you are dragging the mouse and moving it without holding it down you move the mouse look at
that so now what do we know how learn in Java in this little program that took quite a little
ways to build we learn how to respond to the users Mouse events so now we know how to respond
to your keyboard events using scanner and the other stuff we will enter a nice tutorial
and also their Mouse events right now so we can pretty much start building for some pretty
cool programs using you know graphics and stuff like that but for the next tutorial
I’m probably going to be teaching you about layouts how to make super cool windows with
buttons right where you want them and you know more stuff like that but for now thank
you guys for watching my mouse event handling tutorial I hope you learned a little something
of course not too much because I mean come on why would you want to learn a lot I mean
learning not that fun so again thank you guys for watching don’t forget subscribe to my
channel so glad your subscribers so glad thank you for your views don’t forget subscribe
again and I will see you next door what is going on guys welcome to your seventy seventh
Java tutorial and in this tutorial we’re gonna be learning about something called adapter
classes now in the last tutorial when we implemented from the interface like Mouse listener and
Mouse motion listener we had to implement seven different methods and those are kind
of time-consuming in sometimes you don’t always want your program to detect all of those different
methods sometimes you only want your program to be able to tell when the user click something
instead of drag release move you only need one of those so what Java did is in order
to kind of save you some time they made something called an adapter class and what an adapter
class does is it already implements an interface and it overrides it with a method body that
is pretty much a blank body or pretty much a body that does nothing any we’re saying
all right what’s the point of that well in that way when you inherit from an adapter
class you only have to override the methods that you need so it’s pretty cool in the sense
that you don’t have to override all of those seven time-consuming methods like we did before
you only have to override the ones that you’re going to use in the rest whenever you do them
they just don’t do anything at all just like we wanted them to so let me go ahead and show
you guys what I’m talking about gonna make two variables for our program again get all
your imports right here and the first thing they’re both gonna be private variables I’m
gonna put string in details and what this program is gonna do is it’s pretty much just
gonna say how many times well you’ll see what it does but pretty much this details is gonna
tell what’s going to be displayed in the status bar so that’s all you need to know for now
private j label and just put status bar or whatever you named it last time and now we
got two private variables the status bar in the details is pretty much going to be the
text that’s going to appear in your status bar so now we can go ahead and build our constructor
which is like gooey it’s not gonna take any parameters and for the body let’s go ahead
and add a title super title since you should always have a title get their real name it
toodle I mean why not might as well next we can go ahead and build our status bar which
is the only thing we’re really gonna want up here in the window so wow I really miss
that up status bar and set equal to Nu J label and just have the text by default but this
is default it’s just gonna be the first thing that appears um after we start doing the stuff
this is gonna disappear but now let’s go ahead and add this to the window we’ll pad status
bar and of course go ahead and put like borderlayout dot south and now there we go it’ll appear
at the bottom of the screen if you put south we’ll be going over that later and now we
need to add of course the mouse listener just like that add mouse listener in the parameter
it takes here is an object of the class we’re gonna build and we’re gonna be building a
new class called new mouse class and don’t forget your empty parameters for that so make
sure we didn’t miss oh I know we’re getting an error because we didn’t build the class
yet so let’s go ahead and create a class called Mouse class and with this Mouse class we’ll
just go ahead and throw private class Mouse class extends so we need to build a mouse
class because that’s what the parameter it took in in our class we’re gonna pretty much
define how to handle these Mouse events and we want it to extend Mouse adapter in this
adapter class that we’re extending from this is the class that is built in a Java already
so this can be custom whatever you named but this has to mean Mouse adapter you have to
type it just like that and again this adapter class is gonna allow you to overwrite only
the methods that you need to overwrite so let’s go ahead and first the only thing we’re
not gonna want to be working with is public void mouse clicked that’s the only thing we
care about when they click we don’t care when they drag or anything else like that so put
mouse event event oh my god can I not type I mean seriously Mouse event event and let’s
go ahead and type what do we want to happen when they click the mouse well let’s go ahead
and take those details right up here that we’re gonna have and put details set it equal
to string dot format and let’s go ahead and put something it takes two arguments but you
clicked percent D so it’s gonna say you clicked percent D and for present D what we want to
do is take that event which is pretty much means when we click and it put get click count
just like that BAM already filled it in for us so it’s gonna say you clicked five six
18 whatever doesn’t fill in in the end yet so now we’re gonna have to make a if statement
and we’re gonna have three parameters to finish this detail variable so if event and here’s
another kind of confusing thing that is maida down and ever saying all right what the heck
is mated down and what’s it mean well whenever you’re building a Java program you don’t really
know what kind of Mouse the user is using there’s three kind of main Mouse’s there’s
a one-button Mouse like on the Mac a two button which is like old classic or a three button
Mouse in the third button is that scroll wheel so in order to distinguish the types of buttons
that they have you just can’t assume that they’re using all your users are using the
same one so if you ever use the Mac then how they make up for this rice mount I mean the
right mouse button is they have something called meta which is called the command or
Apple key that they can hold down and when they click the mouse that simulates the right
mouse button or they can hold the Alt key and when they click the Alt key and click
their mouse it simulates what is it that all is the center mouse button so that is how
you can tell I mean for now when we click the right mouse button it’s gonna work perfectly
but this pretty much is just for people who use special like one button or two button
mouse is if you have a third three button Mouse then this is pretty much what does so
if meta button is down or is meta down take your details and I know I’m probably just
going to explain it a lot easier just by showing you what the program is while ads at the end
of that details variable so you clicked five it will say for example and then go ahead
and what do we want append alright there we go with rights mouse button so if meta is
down what does mean if they click the right mouse button or if they hold down that meta
key is going to say with the right mouse button else if what else do you want the test event
is alt down just like that let’s go ahead and first put that back and details plus equals
with sensor mouse button and the cool thing about this else by default you don’t have
to test anything because you know it’s just a regular click down with left mouse button
so that’s how you distinguish between the right the center in the left Mouse one for
different types of mice and I spelled details wrong so and now I spelled it right so that’s
all we have to do so now we have a variable called details and it’s a string it starts
with you clicked and says a number and says with the right mouse button either wideout
by either why don’t I just put with embarrassing and then I pretty much this is the beginning
and one of these is the end of the string and now all we have to do is add this to the
screen so put status bar set text and for the text we’re just going to write that details
variable so the status bar is going to set equal to the details variable now we can go
ahead and run it and I can show you guys what it does so says this is default what you put
that by default and I’m gonna go ahead and click my left mouse button now look click
1 2 3 4 5 and then if you move it and click your center look what happens Center center
clicking with my center or in other words my scroll wheel and then go ahead and click
here with your right and if you go ahead and move this then it’s actually a new event so
if you want to make your things go up you’ve got to stay in the same place um if you’re
moving it then actually is a move event so that’s why it resets but that’s your basics
of how to distinguish between the right the center and left and also how to use a mouse
adapter class 2 only overwrite the methods that you want again we only over wrote one
method and we then have to overwrite all seven for our program to work so that’s the power
of a mouse adapter class but for now thank you guys for watching don’t forget to subscribe
and I’ll see you next time what is going on everybody is Bucky and I am kind of sick right
now so if I sound a little stuffy or I blow my nose there in this tutorial then I guess
you guys are just going to have to deal with it but I’m going to teach you some Java in
the mean time so let’s go ahead and get started actually we took a break from gooeys for the
next couple toriel’s I’m going to be teaching you something about files now you can create
and modify files in Java just like most other programming languages if you guys are saying
all right what exactly is a file useful for I’ll give you guys the quick 1/2 of the main
thing it’s useful for so far we created computer programs that use like variables and stuff
like that like store the number 5 and X or store like the name Bucky and um Y or something
like that but once they end their program then all of these variables and methods are
all gone so if we want to like keep it in a database then we actually need to like keep
it in a text file so that way when they run the program again then all their information
is there and they don’t you know it’s not just like a program that you can run once
and it forgets about it that way it can store your information on the computer then when
you run your program again we can automatically load the values and stuff and get them again
so what we going over we’re actually building a program later on but for now let me get
typing some code before I lose you guys so let’s go ahead and import the file class so
Java dot IO dot file or you can import everything well that’s good enough and what the file
class does is this is real simple it doesn’t create files or anything all this class does
is give you info about files like whether it exists um has a couple things like length
the path the parent stuff like that right now what we’re going to be doing is testing
whether a file exists on our computer and this is useful for things like if you’re creating
a program to make a file for the first time if it already exists you don’t want to create
one again or else is going to delete it so you want to see if it’s there first and then
if it’s there you can migrate to it if it’s not there then you can create it so simple
enough what you do is type the file class we’ll name X you can name it whatever you
want and then type new file and what this does is the constructor takes the path of
the file so I actually know that I have a file in C and you actually have to do this
capitalize your director whatever it is and if you do well I’ll show you guys test is
in the directory and I have a file named Greg dot txt right there so normally this would
work and that’s a valid of path name but the thing is you know when we’re working with
strings that that little backslash is the escape character so this is whenever you put
this this is going to try to escape this T and put a tab in G and stuff like this so
what we need to do when we’re working with path names and windows is actually need to
put two backslashes like this and when we do this it views this is only one backslash
because remember whenever we do backslash with a string then it’s going to try to escape
it because that’s just how windows is so actually whenever you do path names do two backslashes
if you’re working with windows if you’re working with Linux I think is a front slash bar I’m
not sure so now now that we have this file that is stored in the variable X we can do
a couple things with what we’re going to be doing this tutorial is simply check if it
exists so along with many of the built-in methods we can do if X well we just did BX
and we’ll just shortcut it right there if X exists and if we hover over this it says
test whether the file or directory pretty much exit exists so if Greg dot txt exists
then what do we want to do let’s go stuffy nose system.out.print line and we can print
something like we can actually have X dot getname and that’ll be pretty cool and we’ll
just add something like exist so it will be like Greg dot txt exists or if it doesn’t
while we’ll insert a file that doesn’t exist later so I can tell you guys what it does
and system.out.print line and we’ll say this thing doesn’t exist and make sure you almost
type everything wrong so which I did so now we can go ahead and run this program and see
what we get it says Greg txt exists and I probably should put a space right there but
I didn’t and what is going on is this if you look at my computer right here and you go
to see test and this is a C and the test is right here a file named Greg dot txt does
exist but what if you had a file name in here like um like that see that’s what I could
think of off the top of my head if you run this and click OK it’s going to say this thing
doesn’t exist so that is how you can pretty much look for files in their existence using
the file name and the exist properties in I also taught you another one the get name
pretty much to get the name of it and that’s a quick cute little tutorial and let’s see
if there’s anything else I didn’t cover and that’s pretty much it for this tutorial and
in the next story I’m actually going to show you guys alright we already test if it existed
or not if a file doesn’t exist then how do we create one I mean of course we can go to
our computer right here and create a file like this but we want to create one in Java
program in language so that’s why I’m going to be teaching you in the next tutorial so
for now thank you guys for watching study this and again review one more time you create
an object from the file class and is this constructor it takes the path the name of
the file and remember when you’re working with strings you got to escape the back then
you test whether it exists if it does exist run load code to do anything and if it doesn’t
exist then you usually in here you want to write code to create the file but for now
I just want to let write a little prompt saying this thing doesn’t exist so thank you guys
for watching I hope you learned a little something don’t forget to subscribe and now we’ll see
you next time what is going on everyone welcome to your 79th java tutorial and in this story
I’m going to show you guys a real quick way on how to create files using Java so pretty
much if you don’t have a file created and we could check for a file using what we learned
in the last tutorial then we usually want to run a program like I’m going to be teaching
it today or in this tutorial to create a file so the first thing we need to do is import
Java dot util and just go ahead and import everything from there and now let’s go ahead
and the first thing we need to do is build a formatter variable so we need to make a
final varial variable format sur type X and you can name it whatever you I just named
everything X because I’m too lazy to type anything that’s more than one letter but I’m
going to name an X and what this is going to do a formatter variable pretty much outputs
strings to a file and it’s pretty much like printf but instead of printing to the screen
your print a file so this pretty much outputs a string and let’s go ahead and I didn’t teach
you guys except I didn’t teach you guys about exception handling but I’m going to have to
do some right now I’ll give you guys the quick one to you pretty much in exception handling
you write try and then you’re right what do you want to try and what we want to try is
this we want to set X equal to new formatter like that in this is pretty much the same
thing as instantiated the variable and same line but we want to try to do it down here
in as the constructor for this is pretty much the same things put final formatter x equals
new formatter and again as a constructor it takes the path of the file so what file do
we want to output to well I’m going to make a file call like Fred dot txt and here’s the
thing if there is no file to output to then automatically creates a file on your computer
for you so that is how you can create files on your computer on your computer using formatter
so again let’s go ahead and now that we created a file we want something to show up in the
command prompt tell us that we did it so system.out.print line and let’s go ahead and put you created
a file so now if we try this and it’s successful then this stuff is going to happen however
if we get an error then and again I’ll be going over this try and catch you later so
don’t worry too much if you don’t extend it understand it however if you get an error
in this an error and exception is the exact same thing they just had to name it exception
because they had to be different if you get an error then what do you want to happen system.out.print
line you got in air so this is pretty much your own way of making custom errors so you
know in if we had an error before then our program would just start running and we’re
get a bunch of error messages on our command prompt but this is a way if we you get an
error running your program that your program doesn’t just automatically shut down and you
can actually handle those errors aka exceptions why they name exceptions I don’t know it’s
annoying but they did it so I know I didn’t teach you guys about try and catch it but
it’s pretty much try this code if you get an error do this BAM you just learned it in
like half a second so what we’re going to do is let me show you guys right here on my
computer if I search in here and I search for Fred I don’t have anything on my computer
named Fred or anything like this but now we’re going to run this program right here and it
says you crested a file and I mean to put created but I did it okay make fun of me big
deal so did we create a file I mean all we’re getting is this command prompt right here
I don’t believe you created a file Bucky well let’s go ahead in this computer here in search
again and now let’s search for Fred and make sure you only have one day and bam look at
this we now have a file created if we click on the properties is created see users Gregg
workspace Bucky and that is pretty much right here and if you’re working with Eclipse you
can highlight Bucky click refresh and under your jRD systems library you get that Fred
text and I know I just talked real fast and you guys didn’t really comprehend that probably
but I should probably slow it down pretty much what I’m saying when you create a file
you created it in whatever directory your program ran from so if you have this Java
program right in your hard drive then it’s going to create this text file right on your
hard drive if you run this Java program from a folder called um like apples or something
then it’s going to create this text file in the folder called apples and you can also
make an absolute path like this and you know well you guys know how to make absolute paths
from let pass for my last tutorial to create that file where you want it like in a folder
or something but again to recap one more time we use this final format or X variable and
what this did is pretty much stored this formatter well it just pretty much created a variable
and again the formatter is pretty much a way of putting strings into a file or pretty much
writing stuff in a file so right now our file is empty but we’re going to be putting stuff
in it later and again if it couldn’t find the file then it created it and that’s why
it created it and again if we made an error then Java makes us handle it in some way so
that’s why I need to teach you guys about try and catch um you can catch different types
of errors like if a user tries to divide by 0 or if they are supposed to input a number
and they actually input letters or something then those are the kind of errors you usually
want to catch and you usually want to send a message back hate it in put a number no
letter but for now we’ll just output you got an error so that is your real quick tutorial
on how to create files we’re actually be clearing this up and no makes sense when we create
a program but and also your real quick tutorial on exception handling try and catch so thank
you guys for watching don’t forget to subscribe if you’re a little confused don’t worry I’ll
clear things up for you in Mexico tutorials but again thank you don’t forget subscribe
and I’ll see you guys next time what is going on guys it is Bucky and welcome to your 80th
Java tutorial in this story I’m going to teach you guys how to add data to your files so
in the last story we pretty much learn how to create an empty file not that useful so
let’s go ahead and put something in it in this tutorial and hold on one second I got
to itching right here I felt good I got it all right so let’s go ahead and import a couple
things we need to import Java dot IO and let’s go ahead and import everything from there
and as you can see I made a separate class outside my main class and I just named it
create file because that’s where we’re going to be doing creating files that’s why I named
did that so next let’s go ahead and put Java dot Lang we need some crap from in there and
lastly let’s go ahead and import Java dot util I’m not exactly sure what we’re going
to be building in this tutorial but this should cover everything so without further ado let
me think what do I want to do first well the first thing we need to do is do a private
formatter variable and I’m going to name on X as usual and what this is going to do is
hold a formatter object and let’s go ahead and make a method to pretty much create and
open a file so let’s go ahead and put public void and we’ll just name it Open File you
name it whatever you want it’s a doesn’t like any parameters because they’re just going
to open a file now in this method what we want to do we got to have our try and catch
block like always so let’s go ahead and try and set X equal to new for Matt’s or object
in go ahead and write a file name um make sure you write one that you don’t already
have a file or else you’re going to overwrite it so I don’t have a file called like Chinese
text you probably don’t either so you can use that so go ahead and try and set this
file equal to X if you can’t let’s just go ahead and catch an exception catch exception
II and this pretty much means if you get an error what do you want to do let’s do system.out.print
line just put you have an air air no error there we go alright so now when we ever recall
this method open file it’s pretty much just going to set X equal to this file it’s pretty
much just going to give us a file so we can use so now we have a file that we can use
so what we want to do to that well we want to add a record to it so let’s go ahead and
put public void add records and let’s go ahead and this is going to take any parameters either
and adding records is the easiest thing in the world all you need to do is put the file
you want to add to which is X because remember we set equal to Chinese dot txt and what you
do is the method is format and this pretty much is like printf for files and now again
how familiar is this the format and the arguments so for the format let’s let’s insert three
strings the first one say we’re making like a user account the first one will be the ID
number so we’ll put like 20 it’s my favorite number and the second one will be my first
name which is Bucky and the third piece of data will be Roberts which is my last name
so I looks good right there so now what this is going to do is insert three elements in
the same line it’s going to say 20 Bucky Roberts it’s going to insert that in our file whenever
we call this method add records and the last thing that we want to do is write a method
to close the file so go ahead and write public void close file or name it whatever you want
but that’s pretty easy to remember and why do we need to put oh I would show you guys
what the thing is X close and closes built-in methods that’s why we can use this and that’s
why we need to include all these so we can use this close method but now let me tell
you guys why we need to close this file it’s pretty much like a housekeeping thing whenever
we exit our program windows usually and I say usually closes our file from writing so
nothing else can write in it but sometimes remember every operating system is different
sometimes depending on your program it can leave the file open it can lead to some errors
so you always want to close your files it’s good programming you always want to do it
I mean you can probably get away with not doing it but if you ever get job as a Java
programmer there are going to be pio to you if you forget to close your files it’s probably
going to cause some errors later down the road so we’re pretty much recap talking about
something different now we’re pretty much got three methods in here we need to open
the file we need to add some records into it and then we need to close the file because
we’re done with it we don’t want anyone else messing with it so go ahead and in your main
or whatever your main method is just go ahead and well we don’t need to include anything
but what we do need is to create an object and I named my class create file so create
firearms can name it like G or something new great file doesn’t take any parameters we
didn’t make a constructor and remember we have three methods you go open file right
there G would rename it add records right there and so now we open the file we added
the records and now what we need to do is close that file because we’re done with it
and now once you go ahead and run this program nothing happens but what it did is created
a file on our computer so if we highlight source are actually Bucky and put file refresh
it’s pretty much going to refresh our computer so now you see we get this Chinese text file
that we just created and the cool thing about eclipse is is actually a text editor as well
so double click this file and I’ll show you what’s in your file and that is 20 Bucky Roberts
this one is just the line number don’t mind that that eyes is actually in the file so
in this text file we have 20 Bucky Roberts so now let’s recap one last time what we did
in create file that Java is pretty much the meat of our program we created a method to
create a file and that was open file right here and we needed a try-catch because of
Java and we said all right we’re going to look for Chinese text that file we want to
write on if we don’t have it already then create a new one so we can write in it and
that’s what X new formatter does so now we have a Chinese text file so we can write text
in it so what do we want to write in it well we just wanted to add a record we gave myself
like an ID number Bucky Roberts and if we had to make like a system of like I had to
make like a library for school or they have like credit card numbers or anything where
you need a ID number you’d add a record after record after record and you called this method
a bunch of times and I just moved that and then that’s how you get like a database on
your computer and then after that you just close your file so you can’t mess with that
anymore and that’s pretty much it so uh thank you guys for watching I hope you learned a
little something and hopefully I got this so you guys can see it but oh well I’m done
with Orion noise so anyways thank you guys as it just said don’t forget to check out
my giveaways and don’t forget to subscribe so I’ll see you next time what is going on
guys welcome to your 81st Jeff torial and we are finally going to learn how to read
stuff from a file so as you can already see I created this Chinese dot txt file and I
added three more records to it so the first one is Bucky the second one is the ID number
and then a name ID number name ID number name so it has four records and a record is pretty
much um a row of data so now let’s go ahead and figure out all right we learned how to
open the file we learned how to write this stuff on this file but we don’t know how to
access it from a Java program so that’s what I’m going to be teaching you today and the
thing I didn’t tell you is before we use scanner that scanner object to read from our keyboard
using system in but we can actually use scanner to read from a file as well so let’s go ahead
and first make a private scanner variable so I’m going to name mine scan or X the cursor
out of the way and now let’s go ahead and just make a method to open the file first
so public void open file and let’s go ahead and put try to open the file so we’re going
to set X and again here’s where we’re going to put a new scanner and instead of putting
a system in here which would be the keyboard just put new file and put that Chinese dot
text I spell it right yep and now instead of reading from your keyboard it’s actually
going to read from this Chinese text file right here so that’s a neat little trick that
you can do and if we get any errors let’s just go ahead and catch those errors exceptions
e and now what do we want to do let’s go ahead and write system.out.print line and let’s
go ahead and print something like good nods fine file looks good enough so now we have
a method to open the file easy enough so what method do we need after this well this tutorial
is all about reading files so let’s go ahead and make a method to read the data from that
file so public void just name it like read a file or something like that and what we
want to do whooping cough the first thing we want to do is create a while loop and go
something like this while I’ll put your file name which is X and then we one-putt has next
and what this is going to do it’s a built in method it’s going to make a while loop
and it’s going to keep going until it reaches the end of the file so it’s going to loop
through this and has next pretty much means if you hover over it on another input so as
long as there’s something there it’s going to continue as soon as there’s nothing there
and it reaches the end of file this is going to be false and this while loop is going to
break out so that’s why we can work right while X has next it pretty much means while
the file X has something in it so what we want to do is you see each of these records
has an ID number a first name and a last name so we’re going to want three variables to
hold those string a and let’s go ahead and copy that actually we’re going to put string
a equals X dot next and what this means is pretty much it’s going to do this well let
me finish writing all my variables that will tell you guys what does string a equals next
and this is going to be B and C what it’s going to do is this it’s going to loop through
the very first thing it sees and it’s going to assign 20 equal to a then it’s going to
assign Buckey equal to B and Roberts equal to C and then we’re we’re going to put after
this is we’re just going to go ahead and print those out so system.out.print actually printf
will be better so let’s go ahead and print just three string variables so percent s space
percent s space percent s in those variables of course are a B and C so now what it’s going
to do is after it gets those three it’s going to print it out in might want to put a new
line there and then it’s going to go all right next 60 a Joe is B in Delta C now I’m going
to print all those out and it’s going to keep printing those out until it gets to the end
of the file which is right here and then it’s going to break out that while loop so that’s
actually the only thing we need in this read file method right there so now we just need
that one last method and what this is going to do is close the file so public void close
file just like that and all we want this to do is close that file X and now looks like
we got everything check for errors and now we can go ahead and start putting it in our
main so let’s go ahead and put read file I didn’t intrude probably yep R equals new read
file don’t take any parameters and now let’s go ahead and put our open file r dot read
file and r dot close file right there so now what this is going to do is call open file
to open it read the stuff from it and close it when we’re done with it so now let’s go
ahead and run this and we’ll see what we got we got pretty much exactly what is in our
text file xx Bucky Roberts it just printed all this out it stored this in a B C printed
it out then it got three new variables store this in a b c print out ABC ABC and then it
got to the end of the file and a broke out so again let me make sure that’s in there
and i’ll tell you guys how this worked one last time we made a new scanner variable x
because remember we can use scanner to not only read from our keyboard also read from
files we then made a method to open the file right here in which how we did that is we
pretty much set this scanner and said we’re reading from this file Chinese dot txt which
is right here and we pretty much set the file equal to X this error is a handling because
we programmed it awesomely and we don’t need air handling because we don’t have any errors
and now we made a method to read the file or pretty much read the data in the file and
how we did this is we pretty much set variables equal to each one of these items or words
or strings choose your word and then when we got three we printed it out on the line
and then we got a new line got three more printed it out three more print it out and
it does that until it reaches the end of the file using the hasnext function and last but
not least we close the file because you know it’s just good programming so that is that
for how to read a file in Java um that’s it I mean nothing else to say except thank you
guys for watching don’t forget to subscribe and I will see you next time what is going
on guys welcome to your 82nd Java tutorial and in this tutorial I will be teaching you
guys about exception handling now what exception handling is pretty much a way to handle errors
now an error and an exception are the exact same things so pretty much why would we want
to handle an air well when the user does something they’re not supposed to do we don’t want to
get in error or else the program which is shut down and it will stop running we want
a way to do something like if they like divide by zero or click something you’re not supposed
to click then we don’t want the program to shut down and we want to be able to tell them
they’re wrong and tell them to fix their mistake so let’s go ahead and I’m going to use scanner
so I’m going to go ahead and import Java util dot I’ll just import everything because I’m
lazy and now let’s just go ahead and let’s begin making our system so scanner I’m going
to name it input equals new scanner and as parameters type system not in and now we have
an input variable called scanner so what do we want to do well let’s just go ahead and
make a little program 2/2 number so system.out.print line and go ahead and print like just give
them from like enter first num and now for the first number in to number one equals input
dot next int BAM and now whatever they type for the first number is going to be the let’s
see numerator and now let’s go ahead and copy this duplicate it and go ahead and set this
equal to num2 and give them a new prompt and our second number and now let’s go ahead and
make a new sum equal to num one divided by num2 so now we got a little program if we
go ahead and print out the sum so system.out.print line and go ahead and print the sum and we’ll
run this and test it make sure it’s working so as I say number one oh here we go so now
let’s go ahead and test this real quick and see if it works okay and our first number
12 and our second number three and it gives us an answer or four so this works fine but
if we run it again and we go 12 in for a denominator we give a zero remember you can’t divide by
zero it gives you an exception like this so this pretty much shuts down our whole program
and what if we build a huge program for like analyzing stock market and that was awesome
and then some idiot tried to divide by zero and the whole thing just shut down well that
wouldn’t be good so we need a way to kind of handle these errors until the user R right
don’t do that but we’re not going to shut down program we’re actually going to fix your
problem well in order to handle exceptions you need to learn something called try and
catch what try and catch means is it pretty much like pretty much just like it is you
try a bit of code and if you have an error you’re instead of shutting down your program
you’re going to catch that error and do something with it so here’s how you do this go ahead
and put try and that’s a key word in in your curly brackets fill in the code that you want
to try so I’m going to try this so in my try block right here I’m going to write the code
that I want to try so I’m going to go ahead and try this and what this tribe means and
what this code block means if you have an error anywhere in here what we want to do
is catch this error so go ahead and write catch after this and there always needs to
be a catch after a try and there can be something called finally – but for now remember there
always needs to be a catch after a try in for catch what do we want to catch we’re going
to want to catch all errors and in order to catch all air errors remember they’re called
exceptions type DX cep tion ii and why do you need to write this there’s actually different
types of errors like arithmetic err I think one is called like input error or something
like that but the like if they make a math error or if they click something wrong they’re
different types of errors but if you want to catch all of them this means if they do
anything wrong at all this is just the broad exception class right here so let’s just go
ahead and catch that in the e is pretty much if you want to print out or something like
that but if they have any errors what do we want to do let’s type system.out.print line
we’ll just type something like um you can’t do that and let me fix this so what this pretty
much means is try this if you have an error do this if not if you try this and it works
good then this is never going to run at all so let me show you that I’m going to try this
and I’m going to enter 12 3 BAM for this catch right here never runs it all but if I run
this again and I get an error and it says 12 0 it says you can’t do that in my rest
of my program if I had any more code down here it would continue to run normally so
what if I actually wanted to build a program so if they entered the wrong thing then I
could pretty much have them do it again over and over again until they enter the right
thing well let’s go ahead and this is really simple but it’s x equals 1 so I’m going to
pretty much have a do-while loop and I’m going to do this do the pretty much the whole trying
catch so catch this and want to catch that too I want to do the whole trying catch while
X that we just made that’s equal to 1 is equal to 1 so I’m going to do that over and over
again while this is equal one but the thing is if it continues to execute successfully
and I’m going to set this equal the X equals two so as soon as it runs successfully I’m
going to set this X equal to two and it says all right that’s the point in time when I
stop so here is a way where we can keep running this program over and over again until we
get the right input so if you had a really dumb user the program would look something
like this run sample all right and our first number 12 um 0 oh you can’t do that try again
ok and our first number again let me expand this a little bit arm 43 of 0 oh nope you
can’t do that enter first number again and it’s going to keep trying and trying so let’s
go ahead and do this right so put like 40 and 10 BAM 4 so that is how we can keep kind
of prompting the user to do it correctly and let me review this one more time how I did
this is I pretty much put all right what do I want to do over and over again well I want
to try this code and if this code runs successfully I’m going to change this variable but if this
code does not run successfully then I’m going to print out an error and this never even
runs since you get an error in this in this and when it tries to divide the sum this is
where the error happens right here on this line so this X never gets set equal to 2 so
that is why X is still equal to 1 and that is why the do-while loop is able to run over
and over again but as soon as this whole thing okay good good good good good good BAM we
finally made all the way X equal 2 and then it looks all right is X equal to none X equal
to 1 nope all right then we can finally exit this bad boy so that’s pretty much your basics
of track catch – pretty much I mean it’s pretty simple try this if you get an error do this
I mean how easy is that um there’s actually a little bit more to it and I’ll probably
be covering the next tutorial but for now thank you guys for watching don’t forget to
subscribe and I’ll see you next time what is going on everybody is bucking welcome to
your 83rd drop tutorial now we’re actually going to be getting back with gooeys and learning
about layouts again after a short break learning about files and exception handling and stuff
like that so in this story I will be teaching guys about something called flow layout and
I know we used before but this time I really want to show you guys the details up so let’s
go ahead and I’m going to make a program that has some buttons on the screen and depending
on what button you click depends on what the full layout is set as so let’s go ahead and
make fruit three variables they’re all going to be private so private J bun and I’ll just
name this like left button and go ahead and copy that and we’re going to name one CB and
RB in this gonna stand for center button and right button so I change this to CB this is
going to be Center button and this is going to be the right button right there so now
that we have three buttons or at least three variables what we need is a flow layout and
a container object so go ahead and make a private flow layout and you can neighbor is
anything you want I’m going to name and layout because it’s easy to remember and also we
need a private container object and I’m going to container just like that make sure I spelled
it right and looks good enough so now we can go ahead and build our constructor and my
classes name layout so I’m going to name public layout for my method and this will be my constructor
so again first thing we do since we’re extending jframe we can go ahead and build our title
using super and I’m just going to name the title because I’m that original and next we
need to go ahead and set our layout object that we created right up here with flow layout
will set layout equal to new flow layout and this pretty much means we want our layout
to go from when we put things in there like buttons we want to be range from left to right
kind of like Microsoft Word would do it so now that we made our new flow layout and we’re
actually going to be changing this depending on what on WordPress but for now that’s good
so now after this we need to set our container object equal to something soap container and
set this equal to get content pane which pretty much means get the bulk of your window and
this is pretty much just so it knows word put the stuff so now let’s go ahead and set
that layout so we’ll set the layout equal to layout and this pretty much means layout
equal set layout new flow layout so I mean simple enough now let’s go ahead in we can
finally do stuff with our buttons this is pretty much creating a window now let’s add
some stuff in it so first thing we need is equal left button set the equal to nu J button
and give it something to put in the button and what goes in your parameters for nu J
button is the text that’s going to appear on the button so my but I have a button on
the screen now that says left on it so now let’s go ahead and add that to the screen
I just kidding I didn’t have it oh but now I do have it on my screen so as I just added
it so now we said it gave us some content and we added it to our screen next let’s add
some functionality to this so we do this by l.b dot add action and look at that it already
made it for us add action listener now we can either write an object in here or to make
things easier let’s use an anonymous inner class and you see said method arm well it
doesn’t give us yet but it needs to use a new action listener and this is the class
and this is again anonymous inner class if I change that and now if you highlight this
it says it must implement the method action listener action performed so if it told us
to do it let’s just do it we’re easily influenced so let’s just go ahead and put something like
well this better method first before we start thinking about that public void action performed
and for our parameter type action event event and now we can go ahead and add some functionality
to this and what do we want to happen whenever we click this left button finally after all
of this adding we finally get to the meet right here the body of our action perform
method what do we want to happen when we click the button well well first of all we want
to change that layout since we click the left button let’s go ahead and set the alignment
and got a nice sort of shortcut right there and what you set it to is flow layout dot
left and what this is going to do is take your entire layout for your window not just
this but not just this button but the entire layout and change everything to left alignment
so by default it’s going to be in the center of the screen and when you click this it’s
going to be on the left so next the only thing we need to do is put layout that we just change
but layout container which is pretty much our container and go ahead and pass container
in this and this pretty much means rearrange everything depending on what our layout is
so now we did this for the left now we can just go ahead and do this two more times and
make it real easy to copy it so I’m actually going to add a comment so I don’t get confused
just pull left stuff in here in here so now let’s go ahead and copy everything included
in that comment and put Center stuff in here and change this the center button add center
button to the screen add action listener for center button and change the flow layout to
Center which is the default but again we need to do that now we need to do it for the right
so let’s put right stuff in here and add the right button to the screen add an action listener
for the right bond again center button and a right button were a lot quicker so and not
that easy house and now let’s go ahead and run this program so what I tell you guys what
I did after I run it I know you guys are probably getting antsy so let’s go ahead and run this
baby and here’s what I got whoa forgot to change my text on my button quite embarrassing
so this is left stuff and I put left-center again don’t forget when you create your buttons
to do that embarrassing so let’s go ahead and now oh my God look at this program here
is my window that I just created right here and as you can see it doesn’t matter if it
resizes it or not it automatically rearranges from left to right and if you run out of realist
acts under each other so now if you see if I click the left it changes it to left right
changes the right and center chooses the center and you can see even if we do this then we
get right left center so it doesn’t really matter how big your window is it just knows
the flow layout depending on the size um where do I want stuff arranged so that’s pretty
much the basics of flow layout and one more time let’s see how much time I have on my
tutorial about two minutes so let me go ahead and walk you guys through this we created
three variables for the buttons and we actually created a flow layout and container object
because we needed them this is just housekeeping stuff for creating a window in your constructor
and let’s just go over one of these we added pretty much some we set the left button variable
equal to a button since you know why not then we added that button to the screen and then
all of this pretty much is just saying all right what do you want to happen when you
click this button and what did we want to happen we wanted to change your layout and
then we want to just reset the container using that so and then we just did it for the center
and right button and here’s my main in case you forgot I included a Java X swing because
that’s the window and well you can see all that you guys already know what this does
already hopefully if you watch my tutorials so that is that for this tutorial thank you
guys for watching don’t forget to subscribe and I will see you next time oh by the way
we’re going to be creating game soon so uh you know just thought I’d let you guys know
but anyways thank you guys for watching and uh don’t forget subscribe what is going on
guys it’s Bucky and welcome to your 84th Jeff tutorial and this story I’m going to be going
over graphics because well my ultimate goal of these tutorials is pretty much make computer
games and we can’t make a computer game without sweet graphics so I’m finally getting into
graphics I decided to abandon flowlayout and stuff for now because you know this is just
much more exciting if we need any other layouts we’ll go back to them but for now I want to
start making some sweet graphics on the screen so let’s go ahead and do that as you can see
I made a new class called peach because well it’ll be quite honest just because I like
peaches and it needs to extend jpanel because we’re going to be using that so don’t forget
to have all your imports now let’s go ahead and get started with making graphics on the
screen now in order to make graphics on the screen we need a method called paint component
and this paint component method is used to draw graphics on the screen so let’s go ahead
and put public void paint component and for a parameter it takes an object from the graphics
class so graphics and I’ll just name a G you can name it whatever variable you want in
this parameter right here this G this is going to be used to like set the color and we manipulate
this object depending on what we want to draw but don’t forget that you need this method
called paint component this is built-in method um that’s inherited and this is the method
used to create all graphics on the screen so now that we have this method we can automatically
start creating graphics so let’s go ahead and get to it the first thing we need to do
is just one other housekeeping thing we need to put super paint component in just fill
in G right there and what this is going to do is it’s going to call the super classes
remember this is how you call super classes methods we want to call the super classes
pink component method and you just need to do this because there’s stuff in the superclass
that we need to use just for housekeeping stuff and pass in your parameter or whatever
it was here and that’s the only kind of confusing thing that might not be self-explanatory so
don’t forget that so now let’s go ahead and get started the first thing we want to do
is set the background color for our screen so go ahead and write this which means this
object set background and bam look at that now is a parameter for your background color
you just take a color now Java already has built-in constants of colors which is pretty
much all your basic colors but for now in order to get constant just put color dot white
because we just want a plain white background so now we pretty much have on our screen a
white background not very exciting but we’re going to change that soon in order to draw
objects on the screen you first need to tell your object or your graphic object what color
you want to use to draw with so let’s go ahead and put G set color and is our parameter just
like set background it takes a color constant now let’s go ahead and set our color to color
blue and make sure blue is in all caps and that means constant in Java so now that we
have a color for our graphics object we can begin drawing a rectangle on our screen so
the first thing I’m going to tell you guys is how to draw a rectangle and to do that
it’s fill ret and what this is going to do is it’s going to give you four parameters
and this is going to draw a rectangle a solid rectangle on the screen so the first parameter
it takes is the X parameter and Y now this top left corner of your window is zero zero
in from left to right this is the X from left to right and Y is up and down so let’s go
ahead and make the coordinates x and y and you should know this if you ever took a math
class in your life so at 25 25 which would be somewhere around here 25 over and 25 down
that is where we want the top-left of the rectangle to be now how why do we want the
rectangle to be let’s just go ahead and put 100 pixels wide by 30 pixels high so now we
got our color and our coordinates of our rectangle right here so now we just have a blue rectangle
chillin on our screen if I want to tell you guys something else you can do next we can
go ahead and put set color and we can set the color again or pretty much reset the color
and if we want to have a custom color that’s not a constant like our own RGB values and
RGB means red green and blue just go ahead and put new color and as our parameters you
type in the RGB value you want so let’s put like 190 commas 81 comma 215 make sure none
of these values go above 255 and this pretty much means all right how much red do we want
it 190 red 81 green and 215 blue what color this is I’m not sure but I know that it’s
going to be some weird color but again if you want custom colors then that’s how you
create it what I usually do is I go in Photoshop and mess around with the RGB value but you
know that’s not important right now so now let’s go ahead and put this rectangle or draw
rectangle Shoji fill repped and again we have to fill in all our parameters so where do
we want to we can’t have it start in the same place so let’s have it like start at 25 over
but we’ll have this one go 65 down since this one ends at 55 again this is the Y and this
is the height so this will give us 10 pixels of padding and you can mess around with this
on your own and we’ll make it the same width and height for you no it’s just nice to be
constant get it constant I just made it up and it’s not even a joke really but anyways
now we have two rectangles chilling on the screen so the last thing I want to show you
guys is that not only rectangles but you can actually draw text on the screen so let’s
go ahead and change our color one more time just because we don’t want everything the
same color on the screen it’s going to be boring set color we’ll just change this color
to like red or something using color dot red is our constant and now let’s just go ahead
and this is how you draw strings or text on the screen G draw string how easy is that
now your iterator is pretty much what do you want the string to say and this is some text
and make sure you spell text wrong or else it won’t work I’m just kidding and now where
do you want to appear well let’s make a x.25 and let’s see 120 that should be below everything
so now we have a rectangle right here a rectangle under it and some text under that so now I
already did this all I forgot I did this all but pretty much make a new frame with your
title set the close operation don’t forget to do that and then make object of your class
whatever you name to add a peach class so I named P add it to the frame set the size
of your window and make sure you set the visible to true so it actually appears and now if
we go ahead and run this program you see that we created two rectangles that were filled
in because we use the method foe rectangle and again if I do this you can see that the
coordinates for the first one the blue one were 25 over 25 down this is a hundred wide
and 30 pixels tall and next we set the color again and we give it our custom color evidently
this is some kind of purple color and this has RGB value of 190 81 215 and this is 25
over 65 down and that’s your top left point right there 100 wide and 30 tall and next
we just pretty much made some text on the screen and this text started at 25 over and
128 pixels down that’s where your text started and then you pretty much just draw drew a
string on the screen using the current color of your G object so that is pretty much the
basics of how do you make simple rectangles of course there’s more stuff we can do but
for now just sticking with the basics in the next story I’m going to show you guys how
to draw some sweet graphics and uh well they’re not gonna be that sweet but they’re going
to be a little better in this one so thank you guys for watching now don’t you subscribe
and hopefully I’ll see you next tutorial what is going on guys welcome to your 85th Jeff
tutorial and in this tutorial I’m going to be teaching you guys about something called
je color chooser now we’re going to be building a program to make a box pop-up and allow the
user to pick their own colors and we’re going to set this color equal to a variable and
just going to be doing some cool stuff of it but this is a really useful application
and we’re going to be using this a lot from now on so you know it’s going to be good so
what we’re going to have pretty much on the screen as a button and when they click the
button they’re going to be able to choose your color so let’s go ahead and make a private
variable refer J button and now just name it be for button since I’m lazy and next we
need a color variable so private color let’s just name it color color variable name the
color and we’ll set it equal to the constant way if I can type takes a little bit I’ll
get there eventually so now we have this color variable set to white and the last thing we
need is pretty much a panel so private J panel and panel we’ll just name it that for simplicity
so we have three variables so let’s start doing some stuff with it um the first thing
we’re going to need to do is build our constructor so name it public peach or whatever your class
is and it doesn’t take any parameters because this constructor no parameters now let’s go
ahead and add a title and the title I cannot type today I apologize for that although I’m
not really sorry suckers and now that we have a title let’s go ahead and make our panel
so take that panel variable you just made and set it equal to new J panel and again
this doesn’t take any parameters either so now we have a panel on the screen pretty much
well we didn’t add it yet but you know we got it and next on our panel we want to set
the background and this is pretty much the background of our window our panel so next
we need to set a background color for it so set back BAM look at that too easy to have
to type anything next we want to set the back ground color and we’re just going to set it
equal to color and what this means is we’re going to set the background equal to white
since our color had the value of color dot white so now we pretty much got a panel chilling
on our screen so now let’s go ahead and add our button to the screen so B equals new J
button doesn’t take let’s go ahead and for the text on our button let’s just put choose
of color because when they click the button they’re going to need to choose a color so
now we can add some functionality to do this so B dot add action listener right there and
is our arguments we’re just going to add an anonymous inner class and let’s go ahead and
just put something like new action I was sure the way they’d have to do this every time
new action listener and again this action listener must implement the method action
performed and then after this we’ll finally get to the good stuff so public void action
performed we did this enough hopefully action event event and now let’s get to the meat
of this story finally so whenever we click this button what do we want to happen well
the first thing we want to do is we want to change that color variable but instead of
changing it to this just like a regular constant or something we’re going to let the user decide
what they want to change it to so we need to put something called J color chooser and
what this allows is the user to choose your color so just put show dialog right there
and this dialog takes three parameters the first parameter is the positioning just put
a null and if you put a null it’s going to appear in the center of your screen the second
parameter is when you click this button um a new box is going to pop up so what do you
want the title of that color chooser to be just pick your color and last the last parameter
is the initial color that’s selected and you’ll see it’s hard to explain because you can’t
see the box but just go ahead and put color right here so whatever the color was set as
before then that’s what we want to have so let’s go ahead and change that and let me
move this over just like that and now we’re good to go but the one thing we have to watch
out for is if they don’t choose a color at all so if we give them an option choose a
bunch of colors and they don’t choose anything we’re going to write all right if the color
that they choose is equal to nothing and this is going to happen if they either hit X or
cancel what do you want to do well we just want to take that color and set it equal to
whatever color it was before or let’s just go ahead and set it equal to white so if they
don’t choose anything then they got white so that’s your fault if you didn’t choose
anything you’re getting white and last but not least we need to change the color of our
background so again the background is pretty much the panel and set back around just like
that and what do we want to change it to whatever color they chose so now outside our action
listener let’s go ahead and add everything to screen panel in I know I guys didn’t teach
you guys about border layout but border layout dot center this means the panel is going to
appear in some of the center of the screen next let’s add our button and that was named
be in border layout in let’s just make this appear in south this means the button appears
at the bottom of the screen set see you’re getting like tutorials for one in here set
size of the window that’s 425 by 150 and once I run this program you guys are going to see
what’s going on set set visible and we’re just going to set this to true so it appears
now let’s run this so I can actually explain it a lot better and again don’t forget to
call your object and set default close operation set okay now we have this program that says
title choose a color again this box is white by default so now if I go to my code right
here we’re going to go ahead and press choose a color now this is going to pop up so we
go ahead and choose a color like blue or something and press ok and now our background has turned
blue and if we click it again choose a color change it to yellow and click OK now our background
goes to yellow and last but not least if you choose it and hit something like X or cancel
it’s white by default so let me go ahead and I’ll explain this if I can get my code to
set up right there what this pretty much means you know what all this means this is a good
stuff we change that color variable according the whatever they wanted to change it do and
again we use that using J color chooser show dialog this is positioning this is the title
of that window right here in again pick your color see that title pick your color right
there and someone’s calling me I’m not going to answer it and then this color is when you
choose a color it’s what’s selected by default so if you click red ok when you do it again
Pink’s going to be or Red’s going to be selected by default and next what this pretty much
does is whenever you pick a color it’s going to store that value in the return value for
color so if you chose black now this color is going to be set to the color black and
so that’s pretty much what that does J color chooser so then you test it if they hit X
or cancel pretty much if they didn’t select any color if they didn’t give them white but
if they did then we want to set that background equal to the color that they chose since that
color variable will now equal whatever value was returned and then we pretty much just
added the panel in the center of the screen right here we added the button to the bottom
we made the size of our window we set as visible so you can see it and then we called it so
that’s your real quick tutorial on how to use J color chooser in essence whatever you
pick right here is going to be stored in this very man that’s all you need to know so thank
you guys for watching we’re going to be using this in our couple tutorials from now on so
make sure you learn it and again one more time thank you guys for watching don’t forget
to subscribe and I will see you next time what’s going on guys welcome to your 86th
Jeff tutorial and in this store I’m going to teaching guys how to draw some more shapes
including like ovals and 3d rectangles but you know when I say 3d wait till you see this
you are not going to be impressed at all it’s pretty pathetic but you know it they had a
thing called 3d rectangles so I had to figure out how to draw it so let’s go ahead in you
know let’s go ahead and get started public and make sure you extend jpanel not jframe
I think we might have done that last time but go ahead and get your public void paint
component again just like that and for a parameter graphics G and now with our paint component
we can actually paint things on the screen so let’s go ahead and well I guess we first
need to call the super dot paint component just like that in G parameter already filled
in for us to call the super classes paint component method and next let’s go ahead and
set background color might as well make it white I’m going to make mine while you can
make yours whatever you want set back around and put color dot watch watch just like dodge
toggle on corner and now let’s go ahead and the first thing I guess I can teach you guys
how to do is draw a basic align on the screen so G dot set color just like that and we’ll
set it to something like blue color dot I mean it’s one of my favorite color so moonlight
in case you were wondering and now let’s go ahead and put G dot draw line and see what
we got for parameters look at X Y and x/y now you know that in order to draw a line
you need two points on the screen this first line this x and y is going to be a coordinates
for the first point this x and y is going to be coordinates for your second point in
java will automatically draw a line from point A to point B so let’s go ahead and put 1025
for the first point which should be somewhere 10 over 25 down and for our second point is
put like two hundred and forty five so it’s going to be a downhill align look something
like this and now we got a line on screen so what else can we draw um G dot set color
we’ll set this one to color dot red because you know got to mix it up a little bit and
now let’s go ahead and put draw or excuse me G dot draw correct and what this means
is unlike last time when we drew a solid rectangle using fill rect this draws a an empty rectangle
and it takes the same parameters as before let’s go ahead and put ten over fifty five
down it will be one hundred wide and it will be 30 pixels tall and now let’s go ahead and
I’m going to teach you guys how to make ovals now now in well let’s go ahead and do this
first set color what color you want to make it guys great you said all right color dot
green so we’re going to have a green oval g dot we’ll make this one solid fill oval
and anytime you have fill and draw they’re pretty much interchangeable depending on personal
preference now this fill oval parameters it takes the exact same parameters as the rectangle
but what it’s going to automatically do is round your corners for you so if we want to
make an oval that’s the same size as this let’s go ahead and move it down a little bit
so we’ll do ten let’s see fifty eighty five so we’ll put it in ninety five that should
give us ten pixels padding and we’ll make it a hundred wide by 30 tall now this is going
to be the same size is this rectangle right here but instead of a rectangle it’s going
to be rounded off at the corners aka and oval so now we got a line a rectangle in and over
in an oval not over E I apologize so the last thing I’m going to teach you guys is something
called a 3d rectangle and what this does is is pretty much a rectangle that’s filled in
but it has a little on bevel on one of the sides to give it a slight appearance that
it’s like pushed out a little bit so puts G dot set color and what do you want to change
the co2 let’s pick good one color dot let’s see that was kind of good on orange BAM that’s
what I’m looking for orange and now let’s go ahead and put G dot fill vamp 3d rectangle
just like this now our parameters this is a little too easy let’s put it 10 over 160
down that’s positioning the width can be 100 just like everything else the height make
this one a little bigger 50 now what this raised means since this is 3d rectangle it
has the option of being raised pretty much means do you want to give it 3d look or not
and of course we do true because 3d is awesome you can also put false to give it not 3d look
but we want this baby looking 3d and you guys are about to be disappointed because this
doesn’t give you nearly as much 3d Z like but if you go ahead and run this program I
already fell – I’m on parameters if you guys need to do this just go ahead and pause but
I did this about 80 times before so you guys should not do that go ahead and as you can
see we drew line from point A to point B we also figured out how to draw a rectangle let
me go ahead and get my good code up here our rectangle using draw rectangle instead of
fill rectangle again fill rectangle would fill this all in with a red we also filled
an oval in using green using the same parameters as our rectangle and last but not least let’s
scroll down here we also made this 3d um rectangle using fill 3 direct now again I don’t even
know if you guys can tell on this tutorial because you to probably take some quality
away but there’s a little line right here along the edge and it’s a little darker than
normal and this is a little than normal on this edge and what this does is give you guys
the 3d effect now again it’s not like 3d like you’re making a 3d button in 3ds Max or something
it’s just a little subtle button like you’d see on a like a very old webpage but you know
it’s a it’s subtle but it’s there so that’s how you make 3d and I’m moving my fingers
like went quoting right now but that’s how you do 3d rectangles and that’s what it means
basically so we’ve learned how to draw a bunch of new stuff on the screen lines rectangles
overs and 3d rectangles it was awesome and so you know it’s been fun but that’s all the
time I have for this tutorial so don’t forget to subscribe and I’ll see you next time what
is going on everybody welcome to your 87th in the last tutorial in Java programming whatever
I named it and this is the last tutorial in Java programming because after this I’m going
to start a new series and it’s going to be like intermediate Java programming because
I mean we can only continue this beginner series for so long there’s so much a job to
go over so this 87th video is the last in this series but after this there’s going to
be like 50 more intermediate videos hopefully if I ever find the time and also there after
that it’s going to be more expert I just can’t have like 200 videos in a playlist or else
it’ll seem kind of weird so that’s why this is going to be a last video in this series
but trust me we’re not done Java yet and aside from this my hard core Java followers are
probably like alright what happened to Java game development I thought we were really
like halfway through that well we’re going to be continuing Java game development but
in the meantime we need to go over some basics because we’re going to be using that in our
game programming so if you’re wondering and worried about all right I want to get back
to game development trust me guys we will build games in Java but first we need some
more basics so what we’re going to be going over in this tutorial is a couple things about
strings and I know we talked about strings before but we never really talked about all
the things that we can do with strings so let’s go ahead and make a couple more strings
right now I’m going to name mine a B and C and I’ll set a equal to apples I said a lot
of things people equal to apples I just notice that string B set this equal to Bucky and
string C set this equal to Bucky but making sure it’s all in caps and spell it right it’s
crucial so now we have string a B and C all right nothing we’ve never seen before now
we already know a couple cool things that we can do like system out print line and we
can get like the length of string using a dot length and let me just test this to make
sure it works good and now there we go and now we can see six right here so I mean we
already learned a few things like how we can get the length using calling the length from
a string class but we can also do a couple more things and the first thing I want to
teach you guys how to do is compare strings now it’s a little different than you guys
might think so let’s go ahead and make it if statement and what you would usually do
is if a is equal to this in whatever you know whatever comparison you want using two equal
signs and this is how we learn to compare things before whenever we compare strings
what we need to do is we need to use the equals method so here’s what you do put a which is
apples if this equals and then in your equals you go ahead and write what you want it to
equal to if a equals apples what you does what do you want to do just go ahead and put
system like let’s go ahead and just copy this smell print line it equals apples put that
in a string so let’s run this and see what we get after we get rid of that there we go
run it and see what we get in it says an error because I didn’t use these two things yet
B or C so that’s why we’re getting that it equals apples BAM so this worked and if you’re
wondering all right you just told me to do that but why can’t I use the two equal sign
well here’s the background for you guys who are just so curious when you use the two equal
signs it how do I say this if two objects are identical which means they have the same
contents but there are two separate objects themselves then it’s going to be false and
this happens a lot in strings and what happened in this case but it’s just it just can cause
a lot of confusion so with the two equal sign just remember if you try to compare with two
equal signs you kept getting an error that means that you have I mean they could be the
same object they go could be both set to apples but if they aren’t the same object then it’s
going to be false so that’s why you always need to use the equals method and that’s why
they built this method for only strings if you’re wondering all right why isn’t this
in any other class because no other class causes problems what the equals method does
is it compares the contents of it and that’s what you always want to do when you’re comparing
strings so I mean BAM that’s that and why did I have these two little things right here
well we can go ahead and compare these by just doing a little quick copy-paste and we’ll
put like if B equals C this is just a demonstrate that you can’t that two strings without the
same casing is different so what do we want to write the keys match right there so if
string B equals string C which are both Buckey let’s see what we get run and it says Lucky’s
match nope we didn’t get a Bucky’s match so let’s go ahead and now we can see that all
right this Bucky does not equal this Bucky but what if we’re writing the computer program
and we want them to like type their name or something and we don’t care about casing and
how can we compare two strings with kind of forgetting about casing what we need to do
is this put equals ignore case and now let’s see what we get and now look at this it says
Bucky’s match so again what I’m trying to demonstrate is anytime you want to compare
two strings and you don’t want to have to worry about case then what you do is put B
equals ignore case and it’s going to compare your two strings just like before but it’s
going to take the case of it and pretty much forget about it say just the contents of Bucky
equals Bucky and matter what casing as you can clearly see so that’s that for this tutorial
and again like I said when you’re moving on from this tutorial don’t look 488 the video
there’s not going to be one you are now ready to go to intermediate Java programming and
I’m going to be building the first tutorial of that next is going to be a continuation
of strings so with that being said I just want to thank you guys you’ve finally made
it through you’ve learned so much Java in this series and I cannot wait to see you next
time so don’t forget to subscribe and I’ll see you then.

100 thoughts to “Java Tutorial from Basic to Advanced in 10 Hours”

  1. I left my phone playing this while im sleeping for five hours……i woke up im at 6:23:24 video content and found my phone so hot and have a battery of 12% after that five hours

  2. I got this error when doing the first gf exercise??https://www.dropbox.com/s/tn5xaa0s1tgi8f2/Screenshot%202019-01-30%2019.41.43.png?dl=0

  3. In part 7 the code won’t work it says The local variable snum may not have been initialized and it won’t let me continue without setting it to a number instead of letting me use the scanner to type it in

  4. I think you got it wrong in the 38th tutorial 3:39:53 , here is why i think so
    the method setTime looked at its local variables before the instance variables and thus changed their values to 4,5,6 then the other two methods made a call to the instance variables which were untouched ; but at 3:43:00 you said that the method looks at the instance variables before the local ones.

  5. Really, thank you ever so much for the tutorial. I was wondering if you could help me figure out how to make a code that runs randomly from 1 to 10, but you only need the code to select out of from 1 to 10 a total of ten only from a random 3 or 4 set of numbers. Eg 2,3, and 5 = 10 or 1,2,3 and 4 = 10 etc . It should not go above the total of ten.
    Thanks.

  6. can somebody help me? I'm getting this message when I try to run my program. "the selection cannot be launched, and there not recent launches". and I don't not why.

  7. WTF tommy and john i told you to create me a class to do this, why does it look like a single cell organism created it….. JK thank you for you hard work speaks sarcastically

  8. 4 and half hours trying to load that positively awful Netbeans dumpster fire. I have Windows 10 – I was able to do all of the equivalent task you said to do, it doesn't work. The internet is positively RIDDLED with huge numbers of users that simply cannot get Netbeans to work. Entire sections of forums have post after post after post of issues installing NetBeans. Is there any instruction on Java available that utilizes a tool that actually works? Thanks!

  9. Very good information. Its very
    useful for me. We have a good career in Java programming. We need learn from
    real time examples and for this we choose good training institute,  we
    need to learn from experts . We need a good training institute for our
    learning .  so people making use of the free demo classes.n
    web designing and developmentn web designing and development

    Many training institute provides free demo classes. One of the
    best training institute in Bangalore is Apponix Technologies.

    https://www.apponix.com/Java-Institute/Java-Training-Institute-in-Bangalore.html

  10. I had to stop watching three minutes in. I just couldn't stand listening any more due to the amount of times you said: "Go ahead and…"
    You may have made a fantastic tutorial but please try to stop using repetitive filler words if you want people to enjoy listening to you!

  11. You sure like food, don't you 😀
    This series of tutorials is great–easy to follow and very beginner friendly.
    Since this is a 10-hour-video and I'm not watching it all in one day, I'd love time stamps in the description. One for each new tutorial, for example.
    Keep up the great work!

  12. Hi Extern Code, can you please help me solve this question?

    You are writing a
    Java program.

    The program must meet
    the following requirements:

     

    ·        
    Obtain
    the numeric value of the string number

    ·        
    Increase
    the value by 5f and assign the result to sum

    How
    should you complete the code?

    String number = “10”;

    int sum = Integer.valueOf(number); + (int) 5f;

    System.out.println(sum);

    The (int) 5f shows an error?

    Thank you

  13. 2:36:50 feels great to be able to hear what he said here, at 1.5x speed not being native speaker/listener xD
    All thanks to Michael Scott 🙂

  14. I keep trying to run it and it just keeps giving me errors…any suggestions

    Errors occurred during the build.

    Errors running builder 'Java Builder' on project 'HelloWorld'.

    java.lang.NullPointerException

  15. I need help at this line of code
    public class tuna {

    private String girlName;

    public void setName(String name) {

    girlName=name;

    }

    public String getName() {

    return girlName;

    }

    public void saying(){

    (Here) System.out.printf("Your first gf was %s/n", getName());

    }

    }

    printf comes back as an error and I have no clue what I'm doing wrong

  16. EDIT:If you're wondering the timestamp of the lesson that I'm describing, it's the lesson at 2:55:00
    During the lesson about using an RNG with an array in a for loop to create program that outputs the frequency of each value in the array's index, I got pretty confused. At first, I didn't understand how the array "freq" stored the amount of times each value in its index occurred. Then I realized that this is because we iterated freq with ++, and that "freq" isn't just an array but it is also an integer that can have a temporary value stored within it that isn't just a representation of its own index. So by iterating freq a thousand times, it not only assigns each slot in its index with a value, but it also counts the amount of times that particular slot within its index occurs, and that's the number that's being outputted by iterating it 1000 times and then outputting the iteration rather than the index value.

    Then I became confused about something else. I understood that when the RNG outputted a number between 1 and 6, it would be stored in the next available slot in freq array's index. That means that freq's index slots 1-6 won't necessarily be 1,2,3,4,5,6. This is because the first number generated by the RNG could be, for example, the number 6. It would then assign 6 to the first available slot in freq's index, which would happen to be slot 1. This made me realize that the number that the RNG generates is really just an arbitrary value that we can assign a separate, metaphorical value after the fact to represent each side of a die. The first side can be 6, the second side can be 3 and so on. The the number generated doesn't truly matter in this case, because what we're focusing on and outputting is the frequency of that particular SLOT in the array's index rather than the value in that slot. Here comes the part that I'm confused about. Upon the realization of how arbitrary the actual values in the index were, I decided just for fun to output all of the values that had been assigned to the array after all the code had been done and all the values had been assigned. Since I placed all of the print line functions after both for loops had completed, all of the values that had been assigned should still be there, right? To my great confusion, some of the slots within the array's index held the same numbers as some of the other slots. For example, slot 1 could hold 4, slot 2 would be 1 etc., but then slot 3 would also have a value 1! I understand that the values that the index holds are arbitrary when assigning something like a metaphorical face of a die but how could freq, as an integer array, count the amount of times a value occurs within its index if its index contains the same value in more than one slot?

    Also, from your prior lesson explaining arrays; I learned that when you create an array, the slots within its index are assigned from 0 to whatever number you specified minus 1. For example, if I created an array with 6 slots, the slots would be referenced from 0 to 5. In the lesson I'm referencing, we created an array with 7 slots, which would be slot 0 to slot 6. Why isn't slot 0 being assigned a value by the RNG? I understand that in the second for loop that we created, we created a counter "int face" and we started it equal to 1, then iterated the int face to be looped until it reached the length of our freq array, which is 6 slots. That's where we get the 6 faces of our die. Then we outputted "freq[face]". From my understanding, outputting freq[face] will display whatever temporary value the freq integer holds(which happens to be whatever index slot is being referenced at the time), and the [face] is what points to the particular slot in freq's index to display the frequency of. All of that makes perfect sense to me, but I'm still confused about one thing. What's stopping freq's 0th slot from being assigned a value?

    And let me say, this is the first lesson I've come across so far that's made me have to think for a long time about the abstractions you have to make when writing in Java. I absolutely love it, and I'm starting to really love object-oriented programming. If someone could answer my questions, I'd be very grateful.

  17. 5- 29:14 – Variable

    6- 36:30 – Input user

    7- 42:05 – basic calculator

    8- 49:19 – Int date

    9- 54:49

    10- 59:54 – if / else

    11- 1:06:00 – Mult. test

    12- 1:12:05 – Switch statement

    13- 1:18:52 – while loops

    14- 1:22:26 – Multiple classe

    15- 1:29:00

    16- 1:35:40 – Multiple methods

    17- 1:43:19 – constructor

    18- 1:49:00 – else nesting

    19- 1:53:57 – else if

    20- 1:58:27 – conditional opperator

    21- 2:01:30 – combine progr. + Average app

    22- 2:04:00 – for .. loop

    23- 2:11:50 – simple progr.

    24- 2:18:38 -(do … while) loop

    25- 2:22:00 – math class

    26- 2:26:49 – random nbr genera.

    27- 2:32:03 – Arrays

    28- 2:39:30 – basic array table

    29- 2:45:18 – Sum all elements of an array

    30- 2:49:19 – Take inputs for array elements

    31- 2:58:02 – Enhance for statement

    32- 3:02:03 – Passing arrays in methods

    33- 3:07:44 – Multi dimensional arrays

    34- 3:11:48 – Multi dimensional arrays continued

    35- 3:19:13 – Variable length argument list

    36- 3:23:48 – Time class

    37- 3:32:45 – Time class continued

    38- 3:39:55 – Controlling access to variables and this keyword

    39- 3:45:41 – Constructor overloading

    40- 3:53:21 – building set hour,min,second method

    41- 4:00:11 – Building interfaces for different operating systems

    42- 4:10:05 – Event handlers

    43- 4:19:56 – Event handlers continued

    44- 4:29:49 – Event handlers continued

    45- 4:39:30 – Polymorphism

    46- 4:47:50 – More about polymorphism

  18. Hello, Please tell me, After writing a program using JAVA , how can we convert the program into something no other person can reverse engineer it and discover our code. ?

  19. When I try to run the program in the command line it gives me an error message at the end, when I click java apples what could be the problem.

  20. You are extremely good in explaining. You tell just enough at each stage and avoid scattering of the content like pro! 10/10.

  21. A question: it wouldn’t make any difference if I would use pre increment or post increment in the roll dice code? Or would it? ++freq[1+rand.nextInt(6)]; or freq[1+rand.nextInt(6)]++… is the first one in any way more preferable in this case than the second one?

  22. Can you make stuff on java + database more and can you explain advance java more that helpful when we want make projects.

  23. One of those videos I have to tuck away and come back to – nice stuff, looking forward to spending 10 hours of my life on it for sure.

  24. brother i need the video for mobile.what i mean is i nne the video how to coding the any mobile usin the java please if you can have time i need the video

  25. So we did all that downloading and searching to GET ECLIPSE oh my lord you can just download it and go through the installation window to get the same thing.

  26. Guys! caption added, it will take a day or two to sync. Till than keep learning and visit to learn more http://bit.ly/2Qb9oRi

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