medium-rxjs-publish-multicast.ts

import { Observable } from "rxjs/Observable";
import { Subject } from "rxjs/Subject";
import "rxjs/add/observable/defer";
import "rxjs/add/observable/of";
import "rxjs/add/operator/multicast";

const source = Observable.defer(() => Observable.of(
  Math.floor(Math.random() * 100)
));

function observer(name: string) {
  return {
    next: (value: number) => console.log(`observer ${name}: ${value}`),
    complete: () => console.log(`observer ${name}: complete`)
  };
}

const m = source.multicast(new Subject<number>());
m.subscribe(observer("a"));
m.subscribe(observer("b"));
m.connect();