Java Programming Tutorial - 27 - Introduction to Arrays Video Lecture | Java Programming Fundamentals: For Beginners - Back-End Programming

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