A pre-test or entry-condition loop

(Display Listing 2.)

A while loop is a pre-test or entry-condition loop.

The conditional test is performed before the code in the body of the loop is executed.

If the test returns true:

The code in the body of the loop is executed and the test is performed again.

If the test returns false:

The code in the body of the loop is skipped and control exits the loop.

Therefore, if the test returns false the first time that it is performed:

The code in the body of the loop won't be executed.