Java Programming Tutorial - 35 - Variable Length Arguments Video Lecture

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
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sure you do that if you want so thank
you guys for watching now see you next
tutorial