usePrevious 
Holds the previous value of a ref.
Usage 
ts
import { usePrevious } from '@vueuse/core'
import { ref } from 'vue'
const counter = ref('Hello')
const previous = usePrevious(counter)
console.log(previous.value) // undefined
counter.value = 'World'
console.log(previous.value) // HelloType Declarations 
typescript
/**
 * Holds the previous value of a ref.
 *
 * @see   {@link https://vueuse.org/usePrevious}
 */
export declare function usePrevious<T>(
  value: MaybeRefOrGetter<T>,
): Readonly<Ref<T | undefined>>
export declare function usePrevious<T>(
  value: MaybeRefOrGetter<T>,
  initialValue: T,
): Readonly<Ref<T>>Source 
Contributors 
Changelog 
v10.0.0-beta.4 on 4/13/20234d757 - feat(types)!: rename MaybeComputedRef to MaybeRefOrGetter10e98 - feat(toRef)!: rename resolveRef to toRefv9.12.0 on 1/29/2023e101f - feat: new function