C++ Classes: Loops in Constructor

[TeTeC]

Hello!

I'm experimenting with classes in C++. It works fine for now, but there is something I can't find an explanation for. I tried to develop a 'matrix' class, and I overloaded some operators in order to define addition or multiplication for matrices. This works like a charm, except for the part where I make a default constructor to initialize my matrix.

In order to do this, I first thought about doing a double loop to initialize all the values in the matrix. In my class CMatrix, the fragment of code is:

	CMatrix () {	
		for (int i = 0; i < ROW; i++){
			for (int j = 0; i < COL; j++){
				matrix[i][j] = 0;
			}
		}
        };

Note: that's how I defined ROW and COL:

#define ROW 3
#define COL 3

However, it doesn't work. The compilation is fine, but at some point when the program is executed, Visual Express opens a windows where it is written:

'Violation of access at 0x00030ffc, etc.' (I can't translate everything, I have the french version of the software, but there is nothing else important to say.)

Since my matrices are 3x3, I tried to initialize all the values by 'brute force':

CMatrix () {	
	matrix[0][0] = 0;
	matrix[1][0] = 0;
	matrix[2][0] = 0;
	matrix[0][1] = 0;
	matrix[1][1] = 0;
	matrix[2][1] = 0;
	matrix[0][2] = 0;
	matrix[1][2] = 0;
	matrix[2][2] = 0;
};

And it works! I don't see any mistakes in my loops (and VE would have found them). So, is there something I am not allowed to do?

Thank you!

 

[TeTeC]

Woops, that's the wrong sub-forum. Could somebody move this thread and delete this message ? Thanks.

 

[quicknote]

Hello! It seems like you are experiencing an issue with your default constructor in your 'matrix' class. It is possible that the issue lies with the way you are initializing your matrix in the constructor. Without being able to see the rest of your code, it is difficult to pinpoint the exact issue. However, there are a few things you can try to troubleshoot this problem.

First, make sure that your matrix is properly declared and initialized in your class. It is possible that you may have missed a step in setting up your matrix variable.

Second, check your loop conditions to make sure they are correct. In your first loop, you have 'i < ROW' but in your second loop, you have 'i < COL'. This may be causing an issue with accessing values outside of the matrix bounds.

Third, double check that your matrix is not being accessed out of bounds in any other part of your code. This could also be causing the issue.

If none of these solutions work, it may be helpful to provide more of your code or to try debugging the program to see where the issue is occurring. Good luck with your experimentation!