how to use the race function from the rxjs library in typescript

To use the race function from the RxJS library in TypeScript, you first need to import it from the rxjs package:

index.ts
import { race } from 'rxjs';
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The race function takes one or more observables as arguments and returns a new observable. When any of the source observables emits a value, the race observable will emit the same value and complete. All other observables will be unsubscribed.

Here's an example of using the race function with two observables:

index.ts
import { Observable, race } from 'rxjs';

const observable1$ = new Observable<number>(subscriber => {
  setTimeout(() => subscriber.next(1), 1000);
  setTimeout(() => subscriber.complete(), 2000);
});

const observable2$ = new Observable<number>(subscriber => {
  setTimeout(() => subscriber.next(2), 2000);
  setTimeout(() => subscriber.complete(), 3000);
});

race(observable1$, observable2$).subscribe(value => console.log(value)); // Output: 1
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In this example, observable1$ emits a value after 1 second and completes after 2 seconds. observable2$ emits a value after 2 seconds and completes after 3 seconds. When we pass both observables to the race function, it returns a new observable that will emit the value from observable1$ because it emits first. The value 2 from observable2$ is not emitted because it comes after the race observable has already completed.