Iteration

Iteration repeats a block of work. A loop may process every item in a collection or continue until a condition changes.

In the help desk system, the same intake flow runs for every incoming event. This extends the control flow from Control flow without changing the behavior of one event.

for each event in incoming_events:
    if event is invalid:
        record validation failure
    else:
        accept ticket

The loop has a clear input, repeated operation, and stopping condition. When reviewing it, ask whether it always makes progress toward stopping and whether it handles an empty collection. An empty batch should produce no accepted tickets, not an accidental first-item access.

Iteration is often a good choice when the repeated steps are straightforward and the state can be represented clearly.