Description: API / rxjs/operators
Transparently perform actions or side-effects, such as logging
import { of } from 'rxjs'; import { tap, map } from 'rxjs/operators'; const source = of(1, 2, 3, 4, 5); //transparently log values from source with 'do' const example = source.pipe( tap(val => console.log(`BEFORE MAP: ${val}`)), map(val => val + 10), tap(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));