do

RxJS 5 do

by Shashi Kumar Nagulakonda

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, 5);
//transparently log values from source with 'do'
const example = source
  .do(val => console.log(`BEFORE MAP: ${val}`))
  .map(val => val + 10)
  .do(val => console.log(`AFTER MAP: ${val}`));
//'do' does not transform values
//output: 11...12...13...14...15
const subscribe = example.subscribe(val => console.log(val));