• Angular

Solution 1. Use the unsubscribe method

@Component({...})
export class AppComponent implements OnInit, OnDestroy {
    subscription: Subscription 
    ngOnInit () {
        var observable = Rx.Observable.interval(1000);
        this.subscription = observable.subscribe(x => console.log(x));
    }
    ngOnDestroy() {
        this.subscription.unsubscribe()
    }
}                    
                    

Solution 2. Use Async | Pipe

@Component({
    ...,
    template: `
        <div>
         Interval: {{observable$ | async}}
        </div>
    `
})
export class AppComponent implements OnInit {
    observable$
    ngOnInit () {
        this.observable$ = Rx.Observable.interval(1000);
    }
}                
                    

Solution 3. Use RxJS takeUntil* operators

@Component({...})
export class AppComponent implements OnInit, OnDestroy {
    notifier = new Subject()
    ngOnInit () {
        var observable$ = Rx.Observable.interval(1000);
        observable$.pipe(takeUntil(this.notifier))
        .subscribe(x => console.log(x));
    }
    ngOnDestroy() {
        this.notifier.next()
        this.notifier.complete()
    }
}