Returns an Observable that emits only the last item emitted by the source Observable.
It optionally takes a predicate function as a parameter, in which case, rather than emitting
the last item from the source Observable, the resulting Observable will emit the last item
from the source Observable that satisfies the predicate.
last<T, D>(predicate?: ((value: T, index: number, source: Observable<T>) => boolean) | null, defaultValue?: D): OperatorFunction<T, T | D>
Parameters
| predicate |
Optional. Default is undefined.
The condition any source emitted item has to satisfy.
|
| defaultValue |
Optional. Default is undefined.
An optional default value to provide if last
predicate isn't met or no values were emitted.
|
Returns
OperatorFunction<T, T | D>: An Observable that emits only the last item satisfying the given condition
from the source, or an NoSuchElementException if no such items are emitted.
Throws
EmptyError Delivers an EmptyError to the Observer's error
callback if the Observable completes before any next notification was sent.
Error - Throws if no items that match the predicate are emitted by the source Observable.
Description
Overloads
last(predicate?: null, defaultValue?: D): OperatorFunction<T, T | D>
Parameters
| predicate |
Optional. Default is undefined.
Type: null.
|
| defaultValue |
Optional. Default is undefined.
Type: D.
|
Returns
OperatorFunction<T, T | D>
|
last(predicate: (value: T, index: number, source: Observable<T>) => value is S, defaultValue?: S): OperatorFunction<T, S>
Parameters
| predicate |
Type: (value: T, index: number, source: Observable) => value is S.
|
| defaultValue |
Optional. Default is undefined.
Type: S.
|
Returns
OperatorFunction<T, S>
|
last(predicate: (value: T, index: number, source: Observable<T>) => boolean, defaultValue?: D): OperatorFunction<T, T | D>
Parameters
| predicate |
Type: (value: T, index: number, source: Observable) => boolean.
|
| defaultValue |
Optional. Default is undefined.
Type: D.
|
Returns
OperatorFunction<T, T | D>
|