Problem with declaring dimensions of a general array? (edited)

[Ashley Kin]

Hi, I'm trying to write a method that accepts accepts a pair of two dimensional arrays of integers as parameters (matrixA and matrixB)
and returns a new array as a sum (matrixC). The sum of matrixA and matrixB is matrixC, where for every row i and column j, C(ij) = A(ij) + B(ij).
I'm having trouble initializing matrixC. How do I set it up so I can edit each "element" of the matrix every time I add?
Thanks for any help!

public static void main(String[] args)
	{
		int[][] matrixA = {{2, 3, 4},{1, 5, 6},{2, 8, 6}};
		int[][] matrixB = {{3, 6, 8},{2, 4, 6},{1, 2, 3}};
		int[][] matrixC = matrixAdd(matrixA, matrixB);
	}
	
	public static int[][] matrixAdd(int[][] matrixA, int[][] matrixB)
	{
		int[][] matrixC = 
		for (int i = 0; i < matrixA.length; i++)
		{
			for (int j = 0; j < matrixA[i].length; j++)
			{
				matrixC[i][j] = (matrixA[i][j])+(matrixB[i][j]);
			}
		}
		return matrixC;
	}

[Mohamed Sanaulla]

You dont have i,j initialized.
You would want to take user input regarding the size of the arrays and then store them into some variables.

Also your matrixC isn't initialized and the method matrixAdd expects another argument and you are passing only two matrices whereas it requires 3.

May be you can try using Lists so that you dont have to worry about the size, but anyways you can manage with arrays also.

And I see that in your matrixAdd you are multiplying the elements?

[Ashley Kin]

Mohamed Sanaulla wrote:You dont have i,j initialized.
You would want to take user input regarding the size of the arrays and then store them into some variables.

Also your matrixC isn't initialized and the method matrixAdd expects another argument and you are passing only two matrices whereas it requires 3.

May be you can try using Lists so that you dont have to worry about the size, but anyways you can manage with arrays also.

And I see that in your matrixAdd you are multiplying the elements?

Thanks for catching my mistakes, I edited my question with my new code.
Now I'm having some trouble initializing matrixC?

[Bear Bibeault]

Ashley Kin wrote:
Thanks for catching my mistakes, I edited my question with my new code.

Please do not do that. Leave the code as is and post updated code in a reply. Thanks.

[Mohamed Sanaulla]

What is the exception/error you are getting? What does that error say?

If you are adding two matrices, what do you think will be the dimension of the resultant matrice? Accordingly you would have to initialize the matrixC
And you need to see to it that both matixA and matrixB are of similar dimension, otherwise you shouldn't proceed with the addition.