while / do-while

Examples

A loop with an unknown number of repetitions:

void main() {
    int n = 100;
    int steps = 0;
    while (n > 1) {
        n /= 2;
        steps++;
    }
    IO.println(steps);
}

Output:

6

do-while checks the condition after the body:

void main() {
    int i = 10;
    do {
        IO.println("runs once: " + i);
    } while (i < 5);
}

Output:

runs once: 10

Notes

If the condition never becomes false, the loop runs forever. An endless loop with an exit condition is written as while (true) { ... if (done) break; }.