<script src="//cdn.bootcss.com/vue/2.1.10/vue.js"></script><div id="app"> {{ message }} <ul> aaaa <li v-for="item in list">{{ item }}</li> </ul> <button @click="message= message + '1'">xxx</button></div>xxxxxxxxxxxxxxxxxxxxnew Vue({ el: "#app", data: { message: "hello" }, watch: { message: function(value){ console.log(value) } }})