多维数组

多维数组

多维数组可以看成是数组的数组，比如二维数组就是一个特殊的一维数组，其每一个元素都是一个一维数组。

二维数组

int a[][] = new int[2][5];

解析：以上二维数组a可以看成一个两行五列的数组。

代码：

public class ArrayDemo04 {
    public static void main(String[] args) {
        int [][] a = new int[3][];
        a[0] = new int[2];
        a[1] = new int[4];
        a[2] = new int[3];
        //int a1[ ][ ]=new int[ ][4];//非法

        int[][] b = {{1,2,3},{3,4},{3,5,6,7}};
        System.out.println(b[2][3]);//7
    }
}

public class Test7 {
    public static void main(String[] args) {
        int[ ][ ] a = new int[3][ ];
        // a[0] = {1,2,5}; //错误，没有声明类型就初始化
        a[0] = new int[] { 1, 2 };
        a[1] = new int[] { 2, 2 };
        a[2] = new int[] { 2, 2, 3, 4 };
        System. out .println(a[2][3]);
        System. out .println(Arrays.toString (a[0]));
        System. out .println(Arrays.toString (a[1]));
        System. out .println(Arrays.toString (a[2]));

        Object[] a1 = {1001,"小高",18,"教授","2-14"};
        Object[] a2 = {1002,"小七",19,"助理","10-10"};
        Object[] a3 = {1003,"小琴",20,"主任","5-5"};
        Object[][] emps = new Object[3][];
        emps[0] = a1;
        emps[1] = a2;
        emps[2] = a3;
        System.out.println(Arrays.toString(emps[0]));
        System.out.println(Arrays.toString(emps[1]));
        System.out.println(Arrays.toString(emps[2]));

        System.out.println("=================");
        for (int i=0; i<emps.length; i++){
            for (int j=0;j<emps[i].length;j++){
                System.out.print(emps[i][j]+"\t");
            }
            System.out.println();
        }

    }
}