vue $set 实现给数组集合对象赋值

// data定义一个集合对象
responseData:[
      {'id':'1','name':'女装','price':115,'num':1,'pic':'../static/img/1.jpg'},
      {'id':'2','name':'男装','price':110,'num':1,'pic':'../static/img/2.jpg'},
      {'id':'3','name':'童装','price':118,'num':2,'pic':'../static/img/3.jpg'}
],

// vue方法请求返回集合对象数据
if(res.data.code === 'ok'){
 that.totals = res.data.data.total;
 that.questionList = res.data.data.list;
 
}

// 赋值操作
for(let val of that.questionList){
//此处为重点
hat.$set(val,'discussAnswer','0');
}

<div v-for="(item,index) in list" :key="index"
>{{item.name}}
</div>
<button @click="changeValue" type="primary">改变值</button>
</div>

data(){
    return {
      list:[
        {name:'29Kun',id:1},
        {name:'299Kun',id:2},
      ]
    } 
  } 

mounted(){
  this.list[2] = {name:'2999Kun',id:3}
  console.log(this.list[0]);
}, 
methods: {
  changeValue(){
    this.$set(this.list,2,{name:'2999kun',id:3})
  }
}