1---
2category: Array
3---
4 
5# useArrayFindIndex
6 
7Reactive `Array.findIndex`
8 
9## Usage
10 
11### Use with array of multiple refs
12 
13```ts
14import { useArrayFindIndex } 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 = useArrayFindIndex(list, i => i % 2 === 0)
23// result.value: 0
24item1.value = 1
25// result.value: 1
26```
27 
28### Use with reactive array
29 
30```ts
31import { useArrayFindIndex } from '@vueuse/core'
32 
33const list = ref([0, 2, 4, 6, 8])
34const result = useArrayFindIndex(list, i => i % 2 === 0)
35// result.value: 0
36list.value.unshift(-1)
37// result.value: 1
38```
39 
40## Type Declarations
41 
42```ts
43export type UseArrayFindIndexReturn = ComputedRef<number>
44/**
45 * Reactive `Array.findIndex`
46 *
47 * @see https://vueuse.org/useArrayFindIndex
48 * @param list - the array was called upon.
49 * @param fn - a function to test each element.
50 *
51 * @returns the index of the first element in the array that passes the test. Otherwise, "-1".
52 *
53 * @__NO_SIDE_EFFECTS__
54 */
55export declare function useArrayFindIndex<T>(
56  list: MaybeRefOrGetter<MaybeRefOrGetter<T>[]>,
57  fn: (element: T, index: number, array: MaybeRefOrGetter<T>[]) => unknown,
58): UseArrayFindIndexReturn
59```
60