empty

Creates an Observable that emits no items to the Observer and immediately emits a complete notification.

Deprecation Notes

Deprecated in favor of using EMPTY constant.

empty(scheduler?: SchedulerLike)

Parameters

scheduler

Optional. Default is undefined.

A SchedulerLike to use for scheduling the emission of the complete notification.

Description

Just emits 'complete', and nothing else.

This static operator is useful for creating a simple Observable that only emits the complete notification. It can be used for composing with other Observables, such as in a mergeMap.

Examples

Emit the number 7, then complete

import { empty } from 'rxjs'; import { startWith } from 'rxjs/operators'; const result = empty().pipe(startWith(7)); result.subscribe(x => console.log(x));

Map and flatten only odd numbers to the sequence 'a', 'b', 'c'

import { empty, interval } from 'rxjs'; import { mergeMap } from 'rxjs/operators'; const interval$ = interval(1000); result = interval$.pipe( mergeMap(x => x % 2 === 1 ? of('a', 'b', 'c') : empty()), ); result.subscribe(x => console.log(x)); // Results in the following to the console: // x is equal to the count on the interval eg(0,1,2,3,...) // x will occur every 1000ms // if x % 2 is equal to 1 print abc // if x % 2 is not equal to 1 nothing will be output

See Also