hot-vs-cold-observables.js

/*** Hot Stream ***/
// there is only "one real" invocation of the stream
const count$ = Rx.Observable.interval(1000).share();

count$.subscribe(x => console.log('A' + x));

setTimeout(() => {
  count$.subscribe(x => console.log('    B' + x));
}, 2000);

// Output:
// -------
// sub A: 0--1--2--3--4--5-->
// sub B: ------2--3--4--5-->


/*** Cold Stream ***/
// each subscriber gets their own invocation
const count$ = Rx.Observable.interval(1000)

count$.subscribe(x => console.log('A' + x))

setTimeout(() => {
  count$.subscribe(x => console.log('    B' + x))
}, 2000);

// Output:
// -------
// sub A: 0--1--2--3--4--5-->
// sub B: ------0--1--2--3-->