项目上让计算[[1,2,3,4],[1,2,3,4],[1,2,3,4]] 相同位的和

let result=[];
let dataArr=[
 [1,2,3],
 [2,2,5]
] 
for (let key in dataArr) {
      dataArr[key].forEach((value, index) => {
        if (result[index] == null || result[index] == "") {//判断是否为空把result,每一项都变为0
          result[index] = 0;//[0,0,0]
        }
        result[index] += value;//[3,4,8]
      })
    }