concatMap
RxJS 5 concatMap
HTML
<script src="https://npmcdn.com/@reactivex/[email protected]/dist/global/Rx.umd.js"></script>JavaScript
const source = Rx.Observable.of(1, 2, 3, 4);
const example = source.reduce((acc,val) => acc + val);
//output: Sum: 10'
const subscribe = example.subscribe(val => console.log('Sum:', val));