Difference between loops?

[QWERTYman]

Say I want to do something in a loop if something is true.
Is this:

while(a){ //assume a is a boolean value
dostuff();
}

different than this:

do{
dostuff();
}while(a)

I see no difference between these.

[boenrobot]

In the second, dostuff() will be executed at least once, regardless of whether "a" is true or not. This is the only difference here.

A little more raw explanation:

while() - check the condition, and if true, execute the code block. Repeat.

do...while() - execute the code block, check the condition, and if true, repeat.

[QWERTYman]

Ah.

[mikeb570]

Like someone else said, it is possible for the while loop to run 0 times, the do while loop will run at least once.

I use it for things like

char input;
do{
      PlayGame();
      do{
           cout << "Play Again? y/n" << endl;
           cin >> input;
      while(input != 'y' && input != 'n');
while(input == 'y');

This could be done using while loops but that would require you to initialize input to 'y' before you enter the loop.