Rx.Observable.prototype.forkJoin(...args, [resultSelector])

Runs all observable sequences in parallel and collect their last elements.


  1. args: (Arguments | Array) - An array or arguments of Observable sequences or Promises to collect the last elements for.
  2. resultSelector: (Function) - The result selector from all the values produced. If not specified, forkJoin will return the results as an array.


(Observable): An observable sequence with an array collecting the last elements of all the input sequences or the result of the result selector if specified.


// Without a selector
var source = Rx.Observable.just(42).forkJoin(
  Rx.Observable.range(0, 3));

var subscription = source.subscribe(
  function (x) {
    console.log('Next: %s', x);
  function (err) {
    console.log('Error: %s', err);
  function () {

// => Next: [42, 2]
// => Completed