Distinct

Returns an Observable that emits all items emitted by the source Observable that are distinct by comparison from previous items.

Syntax

distinct(keySelector?, flushes?): Observable

Parameters	Description
keySelector Optional	Default is undefined. Function to select which value you want to check as distinct.
flushes Optional	Default is undefined. Observable for flushing the internal HashSet of the operator.

Returns

MonoTypeOperatorFunction: A function that returns an Observable that emits items from the source Observable with distinct values.

Example

import { of } from 'rxjs';
import { distinct } from 'rxjs/operators';
 
interface Person {
   age: number,
   name: string
}
 
of(
    { age: 4, name: 'Foo'},
    { age: 7, name: 'Bar'},
    { age: 5, name: 'Foo'}
  ).pipe(
    distinct((p: Person) => p.name)
  )
  .subscribe(x => console.log(x));
 
// Outputs
// { age: 4, name: 'Foo' }
// { age: 7, name: 'Bar' }