RxJS Demo
HTML
<div id="container"></div>
<script src="https://cdnjs.cloudflare.com/ajax/libs/rxjs/5.5.2/Rx.js"></script>
JavaScript
var div = document.getElementById('container');
var stream1 = Rx.Observable.range(1, 2, 3);
var stream2 = Rx.Observable.range(1000, 2000, 3000);
stream1
.scan(function(acc, v) {
return acc + ', ' + v;
}, '')
.subscribe(function(v) {
div.innerHTML = v;
});