mphair mphair - 3 months ago 20
C Question

do...while vs while


Possible Duplicates:

While vs. Do While

When should I use do-while instead of while loops?




I've been programming for a while now (2 years work + 4.5 years degree + 1 year pre-college) and I've never used a do-while loop short of being forced to in the Introduction to Programming course. I have a growing feeling that I'm doing programming wrong if I never run into something so fundamental.

Could it be that I just haven't run into the correct circumstances?

What are some examples where it would be necessary to use a do-while instead of a while?

(My schooling was almost all in C/C++ and my work is in C#, so if there is another language where it absolutely makes sense because do-whiles work differently, then these questions don't really apply)

Edit: To clarify...I know the difference between a while and a do-while. While checks exit condition then performs tasks, do-while performs tasks then checks exit condition.

Answer

If you always want the loop to execute at least once. It's not common, but I do use it from time to time. One case where you might want to use it is trying to access a resource that could require a retry, e.g.

do
{
   try to access resource...
   put up message box with retry option

} while (user says retry);