Rx.Observable.zip(...args, [resultSelector])
Merges the specified observable sequences or Promises into one observable sequence by using the selector function whenever all of the observable sequences have produced an element at a corresponding index. If the result selector function is omitted, a list with the elements of the observable sequences at corresponding indexes will be yielded.
Arguments
args(Array|arguments): Observable sources.[resultSelector](Function): A function which takes the inputs at the specified index and combines them together. If omitted, a list with the elements of the observable sequences at corresponding indexes will be yielded.
Returns
(Observable): An observable sequence containing the result of combining elements of the sources using the specified result selector function.
Example
Without a result selector
var range = Rx.Observable.range(0, 5);
var source = Observable.zip(
  range,
  range.skip(1),
  range.skip(2)
);
var subscription = source.subscribe(
  function (x) {
    console.log('Next: %s', x);
  },
  function (err) {
    console.log('Error: %s', err);
  },
  function () {
    console.log('Completed');
  });
// => Next: 0,1,2
// => Next: 1,2,3
// => Next: 2,3,4
// => Completed