java数组为什么不可以打乱顺序

Question

public class Arrays {

public static void main(String[] args) {
    // TODO Auto-generated method stub
int arrays[][] = {
        {3,4,6,8,6,8},
        {5,3,4,9,9,4},

};
    for (int i = 0; i< arrays.length;i++){
        for (int j =0; j<arrays[i].length; j++){
            int i1 = (int)(Math.random()*arrays.length);
            int j1 = (int)(Math.random()*arrays[i].length);

            int temp = arrays[i][j];
            arrays[i][j] = arrays[i1][j1];
            arrays[i1][j1] = temp;
        }
    }

    System.out.println(arrays);

}

}
为什么不能打乱顺序？

Answer 1

我运行了下下，输入结果打乱了的样
每次的运行结果都不一
9 8 6 8 3 4

6 5 3 4 4 9

如
5 4 8 4 9 8

3 4 6 9 6 3