获得的二维阵列的长度 [英] Getting the length of two-dimensional array

问题描述

我如何得到一个数组的第二维，如果我不知道吗？ array.length 只给出了第一个维度。

How do I get the second dimension of an array if I don't know it? array.length gives only the first dimension.

例如，在

public class B {
    public static void main(String [] main){
        int [] [] nir = new int [2] [3];
        System.out.println(nir.length);
    }
}

我将如何获得 NIR 的第二个方面，也就是3的值

how would I get the value of the second dimension of nir, which is 3.

感谢

推荐答案

的这 3

您已经创建了一个多维数组。 NIR 为int数组的数组;你有长度为3的两个数组。

You've created a multi-dimentional array. nir is an array of int arrays; you've got two arrays of length three.

System.out.println(nir[0].length); 

会给你你的第一个数组的长度。

would give you the length of your first array.

另外值得一提的是，你不必初始化像你一样，这意味着所有的阵列不必是相同长度的多维数组（或存在的话）。

Also worth noting is that you don't have to initialize a multi-dimensional array as you did, which means all the arrays don't have to be the same length (or exist at all).

int nir[][] = new int[5][];
nir[0] = new int[5];
nir[1] = new int[3];
System.out.println(nir[0].length); // 5
System.out.println(nir[1].length); // 3
System.out.println(nir[2].length); // Null pointer exception

这篇关于获得的二维阵列的长度的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！