JavaScript定义和初始化二维数组的三种常用方法

// 直接定义一个 3x2 的二维数组
var matrix = [
  ["A1", "A2"],
  ["B1", "B2"],
  ["C1", "C2"]
];

// 初始化一个 i x j 的二维数组，所有元素初始为空字符串
var i = 3; // 行数
var j = 2; // 列数
var dynamicArray = new Array(i);

for (var row = 0; row < i; row++) {
  dynamicArray[row] = new Array(j);
  for (var col = 0; col < j; col++) {
    dynamicArray[row][col] = ""; // 初始化每个元素
  }
}

// 后续可动态赋值
dynamicArray[1][0] = "Hello";

var arr1 = [1, 2, 3];
var arr2 = [4, 5, 6];
var arr3 = [7, 8, 9];

var combinedArray = [];

for (var idx = 0; idx < arr1.length; idx++) {
  combinedArray[idx] = [arr1[idx], arr2[idx], arr3[idx]];
}

console.log(combinedArray);
// 输出: [[1,4,7], [2,5,8], [3,6,9]]

var threeDArray = [];

for (var x = 0; x < 2; x++) {
  threeDArray[x] = [];
  for (var y = 0; y < 2; y++) {
    threeDArray[x][y] = [];
    for (var z = 0; z < 2; z++) {
      threeDArray[x][y][z] = x + y + z;
    }
  }
}

console.log(threeDArray);
// 输出: [[[0,1],[1,2]], [[1,2],[2,3]]]