二维数组遍历

class Hello2 {
    public static void main(String[] args) {
         int[][] arr = {{1,2,3},{4,5},{6,7,8,9}};
         for (int i = 0;i < arr.length;i++ )
         {
             for (int j = 0;j < arr[i].length;j++ )
             {
                 System.out.print(arr[i][j] + " ");
             }
             System.out.println();
         }
    }
    


}