javascript - 计算javascript中列的索引

Question

我想获得每列二维数组的总和，但我不知道为什么它要添加所有内容。

let vals = [
 [1, 1, 1],
 [1, 1, 1],
 [1, 1, 1]
];
 total = 0;
   for (let i = 0; i < vals.length; i++) {
     for (let j = 0; j < vals.length; j++) {
       total += vals[j][i];
     }
     console.log(total);
   }

输出:

3
6
9

我需要什么:

3
3
3

let vals = [[1, 1, 1], [1, 1, 1], [1, 1, 1]];
total = 0;
for (let i = 0; i < vals.length; i++) {
  for (let j = 0; j < vals.length; j++) {
    total += vals[j][i];
  }
  console.log(total);
}

Answer 1

let vals = [[1, 1, 1], [1, 1, 1], [1, 1, 1]];
total = 0;
for (let i = 0; i < vals.length; i++) {
  for (let j = 0; j < vals.length; j++) {
    total += vals[j][i];
  }
  console.log(total);
  total = 0;
}

内循环完成后，您需要重置总计。