C. Segmentation Fault when function modifies dynamically allocated 2d array

Question

What i need is a function that modifies given pointer to 2d matrix like this:

void intMatrixAll(int row, int col, int **matrix);

Now, a fu

Answer 1

Because modifying matrix inside intMatrixAll() does not modify testMatrix in main(). If you want to be able to modify main's variable, you need to pass a pointer to it. So you need to change intMatrixAll to:

void intMatrixAll(int row, int col, int ***matrix)

Inside intMatrixAll, you'll now need to change matrix to *matrix (and for when you are indexing it, you'll want (*matrix)[...].

Finally, you need to change your call to intMatrixAll to:

intMatrixAll(testArrRow, testArrCol, &testMatrix);

The reason why is that C only supports pass-by-value and pass-by-value does not support the called function changing the value of a variable in the caller.

In order to modify the value of a variable in the caller, you need to pass a pointer to the variable and then have the called function dereference it.