Thread: 2D ARRAY PROBLEM

I have a 2D array called box.

int[][] box = new int [2][3];

Its has elements as follows:

box [0][0] = 1;
box [0][1] = 2;
box [0][2] = 3;
box [1][0] = 1;
box [1][1] = 2;
box [1][2] = 3;

I want to end up after coding with elements in the array as follows:

box [0][0] = 2;
box [0][1] = 3;
box [0][2] = 3;
box [1][0] = 2;
box [1][1] = 3;
box [1][2] = 3;

i.e All elements in each column has had its values
replaced by values from its immediate right hand column

I have tried :

for (int j = 0; j < box.length - 1; j++)
  for (int i = 0; i < box.length - 1; i++)
   box[i][j] = box[i] [j + 1];

but no joy. Any thoughts please??

Originally Posted by av8

but no joy.

That provides zero information. Presumably your code didn't work. Since there is a gazillion reasons why it didn't work we have no idea what your problem is. If you provide details it will help others help you.

Hint: a 2D array is simply a 1D array of 1D arrays.

int[][] matrix = {{1,2,3}, {4,5,6}, {7,8,9}};
for(int outer = 0; outer < matrix.length; outer++) {
    int[] temp = matrix[outer];
    for(int inner = 0; inner < temp.length; inner++) {
        System.out.print(temp[inner] + " ");
    }
    System.out.println();
}

So you can concentrate on 1 dimension instead of 2.

for (int j = 0; j < 2; j++)
for (int i = 0; i < 1; i++)
box[i][j] = box[i] [j + 1];

The above code is now working correctly. Thanks for commenting Junky.

kind regards av8

Do not hard code values like that. It will not work for a 2D array of any other size.