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

<div id="div">

    <input type="text" v-model="username" @keyup.enter="add()">

    <input type="button" value="按钮" @click="add()">

    <div v-show="this.arr.length ==0">暂无留言</div>

    <ul>

        <li v-for="item in arr">{{item}}

            <a href="javascript:;" @click="remove($index)">删除</a>

        </li>

    </ul>

</div>

 <script>

        window.onload = function () {

            new Vue({

                el: '#div',

                data: {

                    username: '',

                    arr: []

                },

                methods: {

                    add: function () {

                        this.arr.unshift(this.username);

                        this.username = '';

                    },

                    remove:function (index) {

                        this.arr.splice(index,1);

                    }

                }

            });

        }

    </script>