1---
2category: Array
3---
4 
5# useArrayMap
6 
7Reactive `Array.map`
8 
9## Usage
10 
11### Use with array of multiple refs
12 
13```ts
14import { useArrayMap } from '@vueuse/core'
15 
16const item1 = ref(0)
17const item2 = ref(2)
18const item3 = ref(4)
19const item4 = ref(6)
20const item5 = ref(8)
21const list = [item1, item2, item3, item4, item5]
22const result = useArrayMap(list, i => i * 2)
23// result.value: [0, 4, 8, 12, 16]
24item1.value = 1
25// result.value: [2, 4, 8, 12, 16]
26```
27 
28### Use with reactive array
29 
30```ts
31import { useArrayMap } from '@vueuse/core'
32 
33const list = ref([0, 1, 2, 3, 4])
34const result = useArrayMap(list, i => i * 2)
35// result.value: [0, 2, 4, 6, 8]
36list.value.pop()
37// result.value: [0, 2, 4, 6]
38```
39 
40## Type Declarations
41 
42```ts
43export type UseArrayMapReturn<T = any> = ComputedRef<T[]>
44/**
45 * Reactive `Array.map`
46 *
47 * @see https://vueuse.org/useArrayMap
48 * @param list - the array was called upon.
49 * @param fn - a function that is called for every element of the given `list`. Each time `fn` executes, the returned value is added to the new array.
50 *
51 * @returns a new array with each element being the result of the callback function.
52 *
53 * @__NO_SIDE_EFFECTS__
54 */
55export declare function useArrayMap<T, U = T>(
56  list: MaybeRefOrGetter<MaybeRefOrGetter<T>[]>,
57  fn: (element: T, index: number, array: T[]) => U,
58): UseArrayMapReturn<U>
59```
60