javascript - js 多维数组转换问题?

Question

let arr=[

[1,3,5],[7,9,12]

];

转换为
let newArr=[

[1,7],[3,9],[5,12]

]

Answer 1

方法一：function reverse(arr) {  let list = [];  for (let i = 0;i < arr[0].length;i++) {    list[i] = [];  }  for (let i = 0;i < arr.length;i++) {    for (let j = 0;j<arr[i].length;j++) {      list[j][i] = arr[i][j]    }  }  return list}let arr = [   [1,3,5],   [7,9,12]]console.log(reverse(arr))方法二：const transpose = (arr) => arr[0].map((col, i) => arr.map((row) => row[i] ?? null));

Answer 2

let arr = [  [1, 3, 5],  [7, 9, 12]];let newArr = arr[0].map((_, i) => arr.map(row => row[i]));console.log(newArr);