stack/v1/packages/mosaic/framework/skills/vueuse-functions/references/usePrevious.md

category

category
Utilities

usePrevious

Holds the previous value of a ref.

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

Type Declarations

/**
 * Holds the previous value of a ref.
 *
 * @see   {@link https://vueuse.org/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>>;