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while

The while keyword begins a conditional loop. It evaluates a condition before each iteration and runs the body while the condition is truthy. The body may not run at all if the condition is initially falsy.

Syntax & Example​

let n = 10;
while n > 0 {
    print(n);
    n -= 1;
}

Use Cases​

  • Repeating work while a condition holds, with an unknown number of iterations.
  • Polling or waiting until a state changes.
  • Combining with break/continue for early exit or skipping.

See also: do, Control Flow.