Iteration

Iteration

while, do-while and for control looping and are sometimes classified as iteration statements. A statement repeats until the controlling Boolean-expression evaluates to false. The form for a while loop is

while(Boolean-expression statement

The Boolean-expression is evaluated once at the beginning of the loop and again before each further iteration of the statement.

Here's a simple example that generates random numbers until a particular condition is met:

This uses the static method random( ) in the Math library, which generates a double value between 0 and 1. (It includes 0, but not 1.) The conditional expression for the while says "keep doing this loop until the number is 0.99 or greater." Each time you run this program you'll get a different-sized list of numbers.