vue--点击当前增加class，其他删除class

<div id="app"><p v-for='(data,key,index) in datas' v-on:click="addClassFun(index)" v-bind:class='{class1:index==qwerqwre}'>{{data.data}}</p></div><script>new Vue({el: '#app',data: {datas: {data1: {data: "测试1",ifAdd: 0},data2: {data: "测试2",ifAdd: 1},data3: {data: "测试3",ifAdd: 2}},qwerqwre:"0"},methods: {addClassFun: function(index) {this.qwerqwre = index;}}})</script>