Referenceinterval
Reference · 04
interval
interval
Emits an incrementing number every N milliseconds.
Signature
interval(period: number, scheduler?: SchedulerLike): ObservableMarble diagram
interval(10): --0--1--2--3-- ...What it does
Every period milliseconds it emits 0, then 1, 2, … It never completes on its own — an "endless" stream. The first value comes after period, not immediately (for an immediate start see timer(0, period)).
When to use
Timers, polling, simple animation, periodic status checks. Almost always combined with take, takeUntil, or switchMap so the stream can be ended.
Gotcha
Without unsubscription or a limiter, the interval ticks forever, keeping the component in memory. In Angular components use takeUntilDestroyed() or takeUntil(destroy$).
See also
timer, take, takeUntil
script.ts
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