vue--点击当前增加class，其他删除class

vue–点击当前增加class，其他删

<div id="app">
  <p v-for='(data,key,index) in datas' @click="addClassFun(index)"  :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>