Emit values from Observable.from on an interval

Question

I have an array of items that I want to emit from an Observable on an interval.

I am using the rxjs library included in Angular 2.

This is my current solution but I feel like there is a reactive method that I am not finding. This solution also continues to produce values after the array is exhausted but it should really complete. Is there some way to drive Observable.from with Observable.interval?:

var array = [1,2,3];

var source = Rx.Observable
    .interval(500 /* ms */)
    .map(function() {
      return array.pop();
    });

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

Output:

"Next:"
3
"Next:"
2
"Next:"
1
"Next:"
undefined

Answer 1

For something simple like that, what you've done is fine except that I'd rather use the index given from interval to read the array at that given index instead of using pop which modify the original array (mixed with reactive programming it's kind of weird, isn't it =) !)

I made you another proposal so you may discover other operators maybe :

const { Observable } = Rx

const myArray = [1, 2, 3]

const interval$ = Observable.interval(500)

Observable
  .from(myArray)
  .zip(interval$)
  .do(([x]) => console.log(x))
  .subscribe(
    () => {},
    () => {},
    () => console.log('Stream ended !')
  )

<script src="https://unpkg.com/[email protected]/bundles/Rx.min.js"></script>