distinct

signature: distinct(keySelector?, flushes?): Observable

Emits items emitted that are distinct based on any previously emitted item.

Ultimate RxJS

Examples

Example 1: distinct without selector

( StackBlitz )

// RxJS v6+
import { of } from 'rxjs';
import { distinct } from 'rxjs/operators';
of(1, 2, 3, 4, 5, 1, 2, 3, 4, 5)
.pipe(distinct())
// OUTPUT: 1,2,3,4,5
.subscribe(console.log);

Example 2: distinct with key selector

( StackBlitz )

// RxJS v6+
import { from } from 'rxjs';
import { distinct } from 'rxjs/operators';
const obj1 = { id: 3, name: 'name 1' };
const obj2 = { id: 4, name: 'name 2' };
const obj3 = { id: 3, name: 'name 3' };
const vals = [obj1, obj2, obj3];
from(vals)
.pipe(distinct(e => e.id))
.subscribe(console.log);
/*
OUTPUT:
{id: 3, name: "name 1"}
{id: 4, name: "name 2"}
*/

Additional Resources

📁 Source Code: https://github.com/ReactiveX/rxjs/blob/master/src/internal/operators/distinct.ts