timer
Creates an Observable that starts emitting after an dueTime and
emits ever increasing numbers after each period of time thereafter.
timer(dueTime: number | Date = 0, periodOrScheduler?: number | SchedulerLike, scheduler?: SchedulerLike): Observable<number>Parameters
| dueTime |
Optional. Default is The initial delay time specified as a Date object or as an integer denoting milliseconds to wait before emitting the first value of 0`. |
| periodOrScheduler |
Optional. Default is The period of time between emissions of the subsequent numbers. |
| scheduler |
Optional. Default is The |
Returns
Observable<number>: An Observable that emits a 0 after the
dueTime and ever increasing numbers after each period of time
thereafter.
Description
Its like interval, but you can specify when
should the emissions start.
timer returns an Observable that emits an infinite sequence of ascending
integers, with a constant interval of time, period of your choosing
between those emissions. The first emission happens after the specified
dueTime. The initial delay may be a Date. By default, this
operator uses the async SchedulerLike to provide a notion of time, but you
may pass any SchedulerLike to it. If period is not specified, the output
Observable emits only one value, 0. Otherwise, it emits an infinite
sequence.
Examples
Emits ascending numbers, one every second (1000ms), starting after 3 seconds
import { timer } from 'rxjs';
const numbers = timer(3000, 1000);
numbers.subscribe(x => console.log(x));Emits one number after five seconds
import { timer } from 'rxjs';
const numbers = timer(5000);
numbers.subscribe(x => console.log(x));