Interval

Creates an Observable that emits sequential numbers every specified interval of time, on a specified SchedulerLike.

period	Optional. Default is 0. The interval size in milliseconds (by default) or the time unit determined by the scheduler's clock.
scheduler	Optional. Default is async. The SchedulerLike to use for scheduling the emission of values, and providing a notion of "time".

import { interval } from 'rxjs';
import { take } from 'rxjs/operators';
 
const numbers = interval(1000);
 
const takeFourNumbers = numbers.pipe(take(4));
 
takeFourNumbers.subscribe(x => console.log('Next: ', x));
 
// Logs:
// Next: 0
// Next: 1
// Next: 2
// Next: 3