RxJS: Switching and Exhausting

ex4. RxJS: Switching and Exhausting.js

var source$ = Observable.timer(0, 200).take(6);

function multBy2Delayed(number) {
  // I take 1000ms to multiply your number by two
  return Observable.timer(1000).map(() => number * 2);
}

// NEW CODE STARTS HERE

var switched$ = source$.switchMap((number) => {
  return multBy2Delayed(number);
});

switched$.subscribe((number) => {
  console.log(number); // will log 10 to console
});