While and Do-While Loops
Learn about the while and the do-while loop constructs in C++.
Several programming tasks consist of executing the same code multiple times. Tasks like moving an object across the screen, iterating through a list of items, searching through data, and performing mathematical operations on a stream of numbers; all consist of a block of code being executed repeatedly till a termination condition is met. C++ allows executing the same code several times using two different loop constructs:
The
whileloop and its variation thedo-whileloopThe
forloop
The while Loop
The while loop is really the only necessary repetition construct. The for loop and the do - while loop, coming up shortly, can be replicated using a while loop.
while ( condition ){//body}
Note: A while statement doesn't use a semicolon at its end. It's because the semicolon is used to terminate statements, and the while statement itself is a control structure that needs to be followed by a block of code to execute as long as the condition is true.
A while loop continues to run as long as the condition inside the parentheses is true. If the condition is true, the code inside the curly braces {} is executed. After executing the last line inside the braces, the program checks the condition again. If it is still true, the code inside the curly braces runs again. This cycle repeats ...