how to use the subscription function from the rxjs library in javascript

To use the subscription function from the rxjs library in JavaScript, you first need to import the required modules:

index.tsx
import { Observable, Subscription } from 'rxjs';
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After that, you can create an Observable and subscribe to it using the Observable.subscribe method:

index.tsx
const myObservable = new Observable(observer => {
  observer.next(1);
  observer.next(2);
  observer.next(3);
});

const mySubscription = myObservable.subscribe(value => console.log(value));
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In this example, we created an Observable that emits three values (1, 2, 3) synchronously using the observer.next method. We then subscribe to it and log each emitted value to the console. The Observable.subscribe method returns a Subscription object that represents the ongoing subscription.

To unsubscribe from the Observable, you can call the Subscription.unsubscribe method:

index.tsx
mySubscription.unsubscribe();
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This will stop the Observable from emitting any more values and release any resources held by the subscription.