identity
function
stable
This function takes one parameter and just returns it. Simply put, this is like <T>(x: T): T => x
.
identity<T>(x: T): T
Parameters
x |
T |
Any value that is returned by this function |
Returns
T
: The value passed as the first parameter to this function
Description
Examples
This is useful in some cases when using things like mergeMap
import { interval, take, map, range, mergeMap, identity } from 'rxjs'; const source$ = interval(1000).pipe(take(5)); const result$ = source$.pipe( map(i => range(i)), mergeMap(identity) // same as mergeMap(x => x) ); result$.subscribe({ next: console.log });
Or when you want to selectively apply an operator
import { interval, take, identity } from 'rxjs'; const shouldLimit = () => Math.random() < 0.5; const source$ = interval(1000); const result$ = source$.pipe(shouldLimit() ? take(5) : identity); result$.subscribe({ next: console.log });
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Code licensed under an Apache-2.0 License. Documentation licensed under CC BY 4.0.
https://rxjs.dev/api/index/function/identity