18 - 实现本地存储函数

[mistacguy]

// 你的答案
<script setup lang="ts">
import { ref, watch } from 'vue';

/**
 * Implement the composable function
 * Make sure the function works correctly
 */
function useLocalStorage(key: string, initialValue: any) {
  const value = ref(localStorage.getItem(key) ?? initialValue);
  watch(value, () => localStorage.setItem(key, value.value));
  return value;
}

const counter = useLocalStorage('counter', 0);

// We can get localStorage by triggering the getter:
console.log(counter.value);

// And we can also set localStorage by triggering the setter:

const update = () => counter.value++;
</script>

<template>
  <p>Counter: {{ counter }}</p>
  <button @click="update">Update</button>
</template>