<div id="app">
   <p>作者: {{ author }}</p>
   <p>书名: {{ title }}</p>
</div>

<script src="https://unpkg.com/vue@next"></script>
<script>
const { reactive, toRefs } = Vue;
/* 为什么这里又从effectEffect换成toRefs了？有什么不同？*/
//const state = reactive({
   const app = Vue.createApp({
      setup(){
         const book = reactive ({
            author: '孙鑫',
            year: '2020',
            title: 'Java无难事',
            description: '让Java的学习再无难事',
            price: '188'
         })
         let { author, title } = book;
         return {
            author,
            title
         }
      }
   })

const vm = app.mount('#app')
</script>

我也不懂标题是什么意思，懵懵懂懂迷迷糊糊

加了toRefs函数就可以改响应式了

<div id="app">
   <p>作者: {{ author }}</p>
   <p>书名: {{ title }}</p>
</div>

<script src="https://unpkg.com/vue@next"></script>
<script>
const { reactive, toRefs } = Vue;
/* 为什么这里又从effectEffect换成toRefs了？有什么不同？*/
//const state = reactive({
   const app = Vue.createApp({
      setup(){
         const book = reactive ({
            author: '孙鑫',
            year: '2020',
            title: 'Java无难事',
            description: '让Java的学习再无难事',
            price: '188'
         })
         let { author, title } = toRefs(book);
         return {
            author,
            title
         }
      }
   })

const vm = app.mount('#app')
</script>