usePrevious

保存 ref 的前一个值。

¥Holds the previous value of a ref.

示例

源代码演练场

counter: 1

previous: 0

用法

¥Usage

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