pluck

Maps each source value to its specified nested property.

Deprecation Notes

Use map and optional chaining: pluck('foo', 'bar') is map(x => x?.foo?.bar). Will be removed in v8.

pluck<T, R>(...properties: (string | number | symbol)[]): OperatorFunction<T, R>

Parameters

properties

(string | number | symbol)[]

The nested properties to pluck from each source value.

Returns

OperatorFunction<T, R>: A function that returns an Observable of property values from the source values.

Description

Like map, but meant only for picking one of the nested properties of every emitted value.

Given a list of strings or numbers describing a path to a property, retrieves the value of a specified nested property from all values in the source Observable. If a property can't be resolved, it will return undefined for that value.

Example

Map every click to the tagName of the clicked target element

import { fromEvent, pluck } from 'rxjs';

const clicks = fromEvent(document, 'click');
const tagNames = clicks.pipe(pluck('target', 'tagName'));

tagNames.subscribe(x => console.log(x));

Overloads

pluck(k1: K1): OperatorFunction<T, T[K1]>

Parameters

k1

K1

Returns

OperatorFunction<T, T[K1]>

pluck(k1: K1, k2: K2): OperatorFunction<T, T[K1][K2]>

Parameters

k1	K1
k2	K2

Returns

OperatorFunction<T, T[K1][K2]>

pluck(k1: K1, k2: K2, k3: K3): OperatorFunction<T, T[K1][K2][K3]>

Parameters

k1	K1
k2	K2
k3	K3

Returns

OperatorFunction<T, T[K1][K2][K3]>

pluck(k1: K1, k2: K2, k3: K3, k4: K4): OperatorFunction<T, T[K1][K2][K3][K4]>

Parameters

k1	K1
k2	K2
k3	K3
k4	K4

Returns

OperatorFunction<T, T[K1][K2][K3][K4]>

pluck(k1: K1, k2: K2, k3: K3, k4: K4, k5: K5): OperatorFunction<T, T[K1][K2][K3][K4][K5]>

Parameters

k1	K1
k2	K2
k3	K3
k4	K4
k5	K5

Returns

OperatorFunction<T, T[K1][K2][K3][K4][K5]>

pluck(k1: K1, k2: K2, k3: K3, k4: K4, k5: K5, k6: K6): OperatorFunction<T, T[K1][K2][K3][K4][K5][K6]>

Parameters

k1	K1
k2	K2
k3	K3
k4	K4
k5	K5
k6	K6

Returns

OperatorFunction<T, T[K1][K2][K3][K4][K5][K6]>

pluck(k1: K1, k2: K2, k3: K3, k4: K4, k5: K5, k6: K6, ...rest: string[]): OperatorFunction<T, unknown>

Parameters

k1	K1
k2	K2
k3	K3
k4	K4
k5	K5
k6	K6
rest	string[]

Returns

OperatorFunction<T, unknown>

pluck(...properties: string[]): OperatorFunction<T, unknown>

Parameters

properties

string[]

Returns

OperatorFunction<T, unknown>

See Also

• map