Vue：Avoid mutating a prop directly since the value will be overwritten whenever the parent..报错

Vue框架的：Avoid mutating a prop directly since the value will be overwritten whenever the parent component re-renders. Instead, use a data or goupuitied property based on theprop’s value.Prop being mutated:"number1"报错

我们想要在Vue框架中实现一个父子通信中的双向绑定，
这是出现错误的源码：

<div id="app">
        <!-- 假如在标签中不需要写东西，那么可以写成单标签<cpnn /> -->
        <cpnn :number1=num1 :number2=num2 />
    </div>

    <script src="vue.js"></script>

    <template id="aaa">
        <div>
            <!-- 这里打印一下组件的内容，来检查一下是否传入成功 -->
            <h2>{
   {
   number1}}</h2>
            <input type="te