More powerful the Subject be caution!
In fact, publish() is just a façade that uses Rx.Subject to carry out its work
interface Subject extends Observable implements Subscription {
}
const subject = new Rx.Subject()
subject.subscribe(x => console.log(`Source 1: ${x}`))
subject.subscribe(x => console.log(`Source 2: ${x}`))
subject.next(0)
Rx.Observable.from([1, 2, 3, 4, 5])
.map(x => x * x)
.subscribe(subject)
Always try to avoid and use usual Observable - Observer couple as far as possible