循环的问题

let resdata = res.data;

          let newcityList = [];
          resdata.map((item) => {
            item.originCities.map((each, index) => {
              newcityList.push({
                name: this.itemChangeName(item)[index],
                value: each.purchaseQuantity,
              });
            });
          });
          this.buildNewChart(newcityList);



itemChangeName(itemVal) {
      let newChildCity = itemVal.originCities.map(function (each) {
        var Cityname = "";
        if (each.originCityName == "市辖区") {
          Cityname = itemVal.originProvinceName;
        } else {
          Cityname = each.originCityName;
        }
        return Cityname;
      });
      return newChildCity;
    },