usePrevious
持有 ref 的先前值。
用法
ts
import { usePrevious } from '@vueuse/core'
import { shallowRef } from 'vue'
const counter = shallowRef('Hello')
const previous = usePrevious(counter)
console.log(previous.value) // undefined
counter.value = 'World'
console.log(previous.value) // Hello
類型宣告
typescript
/**
* Holds the previous value of a ref.
*
* @see {@link https://vueuse.dev.org.tw/usePrevious}
*/
export declare function usePrevious<T>(
value: MaybeRefOrGetter<T>,
): Readonly<ShallowRef<T | undefined>>
export declare function usePrevious<T>(
value: MaybeRefOrGetter<T>,
initialValue: T,
): Readonly<ShallowRef<T>>
原始碼
貢獻者
變更日誌
v12.8.0
on 3/5/2025v12.0.0-beta.1
on 11/21/2024v10.0.0-beta.4
on 4/13/20234d757
- feat(types)!:將 MaybeComputedRef
重新命名為 MaybeRefOrGetter
10e98
- feat(toRef)!:將 resolveRef
重新命名為 toRef
v9.12.0
on 1/29/2023e101f
- feat:新增函式