c/language/while

Executes a repeatedly, until the value of  becomes equal to zero. The test takes place before each iteration.

Explanation
A statement causes the  (also called the loop body) to be executed repeatedly until the  (also called controlling expression) compares equal to zero. The repetition occurs regardless of whether the loop body is entered normally or by a into the middle of.

The evaluation of takes place before each execution of  (unless entered by a goto). If the controlling expression needs to be evaluated after the loop body, the may be used.

If the execution of the loop needs to be terminated at some point, can be used as a terminating statement.

If the execution of the loop needs to be continued at the end of the loop body, can be used as a shortcut.