switchMap in rxjs

switchMap is a RxJS operator that is used to handle higher-order Observables. It takes an input Observable and returns an output Observable, where each input value is transformed into an output Observable. When a new input value arrives, switchMap automatically unsubscribes from the previous input Observable and subscribes to the new one.

The switchMap operator is often used when you have an Observable that emits values that are themselves Observables (i.e., a higher-order Observable). switchMap then "switches" to the most recently emitted inner Observable and unsubscribes from the previous inner Observable.