Java二维数组简单定义与使用方法示例

public class MultiDimArray{  public static void main(String[] args) {    int[][] arr = new int[3][];    arr[0] = new int[] { 1 };    arr[1] = new int[] { 1, 2, 3 };    arr[2] = new int[] { 3, 4 };    for (int[] a : arr) {      for (int i : a) {        System.out.print(i + " ");      }      System.out.println();    }  }}