v-for中key的作用

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title></title>
    <style>
        .userList {
            border: 1px solid red;
            margin: 10px auto;
            padding: 10px 10px;
        }
    </style>
</head>
<body>
    <div id="app"></div>
    <script src="./vue.js"></script>
    <script src='./lodash.min.js'></script>
    <script>
        Vue.component('my-com', {
            template: `
                <div class="userList">
                    <div class="content">
                        <h3>{{ obj.name }}</h3>    
                        <p>{{ obj.content }}</p>
                        
                    </div>
                    <div>    
                        <input placeholder='请输入您的姓名'>
                    </div>
                </div>
            `,
            props: {
                obj: Object
            }
        })
        var App = {
            data(){
                return {
                    datas: [
                        {id: 1, name: 'Sunny', content: 'I am Sunny!'},
                        {id: 2, name: 'Jerry', content: 'I am Jerry!'},
                        {id: 3, name: 'Tommy', content: 'I am Tommy!'},
                        {id: 4, name: 'Marry', content: 'I am Marry!'},
                    ]
                }
            },
            template: `
                <div> 
                    <button v-on:click='change'>改变顺序</button>
                    <my-com v-for = '(item,index) in datas' :obj = 'item' :key = 'item.id'></my-com>
                </div>
            `,
            methods: {
                change: function(){
                    this.datas = _.shuffle(this.datas)
                }
            }
        }
        new Vue({
            el: '#app',
            template: `
                <App />
            `,
            components: {
                App
            }
        })
    </script>
</body>
</html>
v-for中key的作用

推荐阅读
