我如何在javascript中声明二维数组？ [重复]

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How can I create a two dimensional array in JavaScript? 40 answers
如何在JavaScript中创建二维数组？ 40个答案

I would like to know how to declare 2 dimensional arrays in java script of fixed lengths something like,

我想知道如何在固定长度的java脚本中声明二维数组，如，

var array = new Array[this.rows, this.columns];

after that i would like to get the length of each dimension like,

之后，我想得到每个维度的长度，如，

array[0].length; // i am assuming this would give me the first dimension like in C# array.GetLength(0);
array[1].length; // i am assuming this would give me the second dimension like in C# array.GetLength(1);

any help is appreciated, thanks.

任何帮助表示赞赏，谢谢。

5 个解决方案

#1

A quick example of what @SLaks is referring to with jagged arrays. You basically put an array in an array. The below example shows one way to make an array thats 100x100.

@SLaks指的是锯齿状数组的快速示例。你基本上把数组放在一个数组中。下面的示例显示了一种制作100x100阵列的方法。

var arr = [];
for(var x = 0; x < 100; x++){
    arr[x] = [];    
    for(var y = 0; y < 100; y++){ 
        arr[x][y] = x*y;    
    }    
}

console.log(arr[10][11]);

Live Demo

现场演示

This method is very flexible for instance arr[4] could have an array indexed to 10, and arr[5] could have an array with 1 value, or be even be a completely different type such as a string or number.

这种方法非常灵活，例如arr [4]可以有一个索引为10的数组，而arr [5]可以有一个数值为1的数组，或者甚至是一个完全不同的类型，如字符串或数字。

#2

Unlike C#, Javascript does not support multi-dimensional arrays.

与C＃不同，Javascript不支持多维数组。

Instead, you can use nested ("jagged") arrays.

相反，您可以使用嵌套（“锯齿状”）数组。

#3

In javascript:

在javascript中：

var Matrix = function (rows, columns)  {
    this.rows = rows;
    this.columns = columns;
    this.myarray = new Array(this.rows);
    for (var i=0; i < this.columns; i +=1) {
        this.myarray[i]=new Array(this.rows)
    }
    return this.myarray;
}

var m = new Matrix(2,2);
m; // [[undefined, undefined], [undefined, undefined]];

var m2 = new Matrix(3,3);
m2; // [[undefined, undefined, undefined], [undefined, undefined, undefined], [undefined, undefined, undefined]]

#4

A nested 3x3 array (of undefined):

嵌套的3x3数组（未定义）：

var arr = new Array(3);
for (var i = 0; i < arr.length; ++i) {
  arr[i] = new Array(3);
}

console.log(arr);

modle13 commented that you're restricted to a fixed size sub-array, so here's one quick tweak to get around that:

modle13评论说你被限制在一个固定大小的子阵列，所以这里有一个快速调整来解决这个问题：

var nestedSizes = [3,5,1,4];
var arr = new Array(nestedSizes.length);
for (var i = 0; i < arr.length; ++i) {
  arr[i] = new Array(nestedSizes[i]);
}

console.log(arr);

#5

-3

could you not just do something like this?

你能不能做这样的事吗？

var x = new Array(4);             #1st array, array of arrays                              
y = new Array(1, 4, 2, 0);       #2nd dimension of arrays, an array of values                  
z = new Array(4, 8, 3, 9);       #^^^                       
a = new Array(7, 0, 2, 4);       #^^^                  
t = new Array(9, 0, 3, 1);        #^^^

then to access 7 (the 1st value) in array a (3) you could type:

然后在数组a（3）中访问7（第1个值），您可以键入：

var example = x.3.1

if this wont work please tell me cos this is what i was told and what im now using to program my game

如果这不起作用请告诉我，这是我被告知的，以及我现在用来编程我的游戏

#1