Visual Basic Tutorial - 33 - More On Do Loops Video Lecture | Mastering Visual Basic - Web Development

hello YouTube sam here from youtube.com
slash on live gamer for the new Boston
and in this tutorial we're going to be
taking a look at some variants of the
Duan tail and they do while loop now
let's go ahead and get started we'll
create a new project make sure you have
selected console application and we'll
go ahead and name this more do loops and
just go ahead and click OK now let's
wait for that to load and then zoom in
ok so if you remember from the last
tutorial we covered the do-while loops
now let's say you have a block of code
and you want that block of code to run
no matter what once and then continue
looping based on if a certain value is
true now the problem with the do-while
loops and the do until loops that we
learned is that it may or may not run
once so let's say do until num1 is equal
to ten well what if no one is already
equal to ten it's not going to loop at
all so I'll show you how to make the
code run once no matter what so we're
going to go ahead and type console dot
write line and we'll just print normal
do until loop so let's go ahead and
create a variable here we'll just call
it num one and we'll set that equal to
zero and then we'll make our do until
loop so do until num 1 is equal to 5 and
then we can just go ahead and do num 1
plus equals 1 and then we'll go ahead
and print out num 1
so this is going to start out printing
the number one on here because we call
num one plus equals one before we wrote
it out on the console so now let's
create a do until loop that will run no
matter what one time so let's just give
us some space right here now let's go
ahead and label this so we'll do a
console dot write line do until variant
okay so now let's create our do until
loop so we're going to start off with
the keyword do and we're not going to
add until at the top of the loop we're
just going to go ahead and hit enter and
you can see it fills in loop for us and
we'll just type console dot write line
num1 so let's go ahead and set num1
equal to ten so after this loop after
this has looped right here and it's
printed out everything and it's done
doing that we're just going to go ahead
and set num1 equal to 10 so we can use
it with this do until loop here now
there's something missing from this we
just have to do and we just have loop
where are we going to put the until well
if we put it down at the bottom then
what it's going to do is going to do
this line right here no matter what and
then it's going to loop until num1 is
equal to 10 so if it starts out that num
1 is equal to 10 then it won't matter
because it'll do it anyways no matter
what num 1 is equal to so if we go ahead
and run this program is going to close
out really quick so let's go ahead and
do console dot readline
okay so you can see here that it's got
the normal due until loop which goes 1 2
3 4 5 and then we've got our do until
variant and you can see that it prints
out 10 here because we added do before
the loop until now we can go ahead and
do this with a do-while loop so we can
pretty much just change this to loop
while num 1 is less than 10 so it's
going to do this once it's going to
print out 10 and it's going to realize
Oh num 1 is greater than 10 so we're not
going to go back up here and loop it
again so if we run this going to get the
normal do until loop which prints out 1
2 3 4 5 and then I'll do until variant
which is going to print out 10 so you
can go ahead and make a couple practice
programs using normal d12 loops
normal do-while loops you can add the
while in the until down at the bottom if
you want and then once you got that
nailed down and you won't forget it go
ahead and move on to the next tutorial
and thanks for watching guys