RxJS - Transformation Operator switchMap

In the case of switchMap operator, a project function is applied on each source value and the output of it is merged with the output Observable, and the value given is the most recent projected Observable.

Syntax

switchMap(project_func: function): Observable

Parameters

project_func − It takes in project_func as the argument which is applied to all the values emitted from source observable and returns an Observable.

Return value

The return value is an Observable, that has values based on the project_func applied on each value of source observable.

Example

import { of} from 'rxjs';
import { switchMap } from 'rxjs/operators';

let text = of('Welcome To');
let case1 = text.pipe(switchMap((value) => of(value + ' Tutorialspoint!')));
case1.subscribe((value) => {console.log(value);});

Output