vue中有关数据监听与数据交互的小例子

 new Vue({
                el:"#div",
                data:{
                   arr:[1,2,3]
                }
            }).$watch("arr",function () {
                alert("数据改变了")
            })

<div id="div">
<input type="button" value="改变" @click="arr.push(5)">
<h1>{{arr}}</h1>
</div>

 a{
            text-decoration: none;
            color: black;
        }
        #div{
            text-align: center;
            padding-top: 50px;
        }
        input{
            height: 25px;
            width: 500px;
            border-radius: 5px;
            outline: none;
        }
        ul{
            margin-left:470px;
            margin-top: 0;
        }
        li{
            height: 25px;
            text-align: left;
            border:1px solid gray;
            list-style: none;
            width: 500px;
        }

new Vue({
                el:"#div",
                data:{
                    msg:" ",
                    arr:[]
                },
                methods:{get:function () {this.$http.jsonp('',{
                            wd:this.msg
                        },{
                            jsonp: 'cb'}).then(function(res){this.arr=res.data.s
                        },function(s){
                            console.log(s);
                        });
                    }
                }
            })

<div id="div">
<input type="text" v-model="msg" @keyup="get()">
<ul>
    <li v-for="item in arr"><a href="javascript:;">{{item}}</a></li>
</ul>
</div>