Java Programming Tutorial - 24 - do while Loops Video Lecture | Java Programming Fundamentals: For Beginners - Back-End Programming

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