Rx.Observable.prototype.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 or an array have produced an element at a corresponding index.
The last element in the arguments must be a function to invoke for each series of elements at corresponding indexes in the sources.
Arguments
args(Arguments|Array): Arguments or an array of observable sequences.[resultSelector](Any): Function to invoke for each series of elements at corresponding indexes in the sources, used only if the first parameter is not an array.
Returns
(Observable): An observable sequence containing the result of combining elements of the sources using the specified result selector function.