vue-v-for的key值为什么会一直重复？

Question

AB是两个tab页，切换的时候已经把addlist致为空数组了，js部分打印index值为啥是undefined？求解

<div class="tit">区域编号 A</div>
      <div class="item" v-for="item in addList" :key="item.index" v-if="addList.length>0">
        <el-input v-model="item.shelves_number" disabled></el-input>
        <el-input v-model="item.shelves_layer" disabled></el-input>
        <el-input v-model="item.shelves_layer_num" disabled></el-input>
        <span>{{item.shelves_num}}</span>
        <span><button @click="delBtn_2(item.index,addList)">删除</button></span>
 </div>

<div class="tit">区域编号 B</div>
      <div class="item" v-for="item in addList" :key="item.index" v-if="addList.length>0">
        <el-input v-model="item.shelves_number" disabled></el-input>
        <el-input v-model="item.shelves_layer" disabled></el-input>
        <el-input v-model="item.shelves_layer_num" disabled></el-input>
        <span>{{item.shelves_num}}</span>
        <span><button @click="delBtn_2(item.index,addList)">删除</button></span>
 </div>

js部分

delBtn_2(index,data){ 
      console.log(index);
      data.splice(index,1);
      this.setList.splice(index,1);

Answer 1

你的addList里面没有index属性吧

Answer 2

自己加上index，v-for=（item，index) in addList