usePrevious

refの前の値を保持します。

使用法

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