Call next() from outside of the Observable using Subject

import { Subject } from 'rxjs';

const subject = new Subject<number>();

subject.subscribe({
  next: (v) => console.log(`observerA: ${v}`)
});
subject.subscribe({
  next: (v) => console.log(`observerB: ${v}`)
});

subject.next(1);
subject.next(2);

// Logs:
// observerA: 1
// observerB: 1
// observerA: 2
// observerB: 2

References
https://stackoverflow.com/questions/41859189/angular2-observable-how-to-call-next-from-outside-of-the-observables-construc
https://rxjs-dev.firebaseapp.com/guide/subject