zrób i dotknij operatora RXJS
const source = of(1, 2, 3, 4);
source.pipe(
tap(val => console.log('I am tap: ',val)),
filter(val => val > 2),
map(val => val + 1)).subscribe((val) => {
console.log('I am subscriber value after filtering: ', val);
});
Motionless Monkey