请问我点击一次可以出现第二次就报错

Question

 <ul>
                  <li v-for="goods in oftenGoods" :key="goods" @click="addOrderList(goods)">
                    <span>{{goods.goodsName}}</span>
                    <span class="o-price">{{goods.price}}</span>
                  </li>
 </ul>

 methods:{
    addOrderList(goods){
      // 商品是否以及存在于订单列表中
      let isHave=false;
      for (let i = 0; i < this.tabdata.length; i++) {
        if (this.tabdata[i].goodsId==goods.goodsId) {
          isHave=true;
        }
        
      }

      // 根据判断的值编写业务逻辑
      if (isHave) {
        // 改变列表商品数量
        let arr = this.tabdata.filter(a=>a.goodsId == good.goodsId);
        arr[o].count++;
      }else{
        let  newGoods={goodsId:goods.goodsId,goodsName:goods.goodsName,price:goods.price,count:1}
        this.tabdata.push(newGoods);
      }
    }
  }

Answer 1

你打印一下arr