查找所有数组多维数组的长度，Java

I would like to use a multidimensional array to store a grid of data. However, I have not found a simple way to find the length of the 2nd part of the array. For example:

我想使用多维数组来存储数据网格。但是，我还没有找到一种简单的方法来查找数组第二部分的长度。例如：

boolean[][] array = new boolean[3][5];
System.out.println(array.length);

will only output 3.

只输出3。

Is there another simple command to find the length of the second array? (i.e. output 5 in the same manner)

是否有另一个简单的命令来查找第二个数组的长度？（即以相同的方式输出5）

5 个解决方案

#1

Try using array[0].length, this will give the dimension you're looking for (since your array is not jagged).

尝试使用array [0] .length，这将给出你正在寻找的维度（因为你的数组没有锯齿状）。

#2

boolean[][] array = new boolean[3][5];

Creates an array of three arrays (5 booleans each). In Java multidimensional arrays are just arrays of arrays:

创建一个包含三个数组的数组（每个数组为5个布尔值）。在Java中，多维数组只是数组的数组：

array.length

gives you the length of the "outer" array (3 in this case).

给出“外部”数组的长度（在这种情况下为3）。

array[0].length

gives you the length of the first "inner" array (5 in this case).

给出第一个“内部”数组的长度（在这种情况下为5）。

array[1].length

and

和

array[2].length

will also give you 5, since in this case, all three "inner" arrays, array[0], array[1], and array[2] are all the same length.

也会给你5，因为在这种情况下，所有三个“内部”数组，数组[0]，数组[1]和数组[2]都是相同的长度。

#3

array[0].length would give you 5

array [0] .length会给你5

#4

int a = array.length;

if (a > 0) {
  int b = array[a - 1].length;
}

should do the trick, in your case a would be 3, b 5

应该做的伎俩，在你的情况下，将是3，b 5

#5

You want to get the length of the inner array in a 3 dimensional array

您希望在三维数组中获取内部数组的长度

e.g.

例如

int ia[][][] = new ia [4][3][5];
System.out.print(ia.length);//prints 4
System.out.print(ia[0].length);//prints 3
System.out.print(ia[0].[0].length); // prints 5 the inner          array in a three  D array

By induction: For a four dimensional array it's:

通过归纳：对于四维数组，它是：

ia[0].[0].[0].length

......

#1