C++: getting the row size of a multidimensional array passed to a function

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I'm trying to write a function that will print out the contents of a multidimensional array. I know the size of the columns, but not the size of the rows.

EDIT: Since I didn't make this clear, the arrays passed to this function are NOT dynamically allocated. The sizes are known at compile time.

I am testing it using a 3x2 array. Here is the function as it stands:

void printArrays(int array1[][2], int array2[][2]) {
    for (int i = 0; i < 3; i++) {
        for (int j = 0; j < 2; j++) {
            cout << "\narray1[" << i << "][" << j << "] = "
                 << setfill('0') << setw(2) << array1[i][j]
                 << "\tarray2[" << i << "][" << j << "] = "
                 << setfill('0') << setw(2) << array2[i][j];
        }
    }
}

Obviously, this only works if I know the size of "i" is 3 (it is in this case). Ideally, however, I would like the function to work no matter what the size of the first dimension.

I thought I would be able to do this using the sizeof() function, e.g.

int size = sizeof(array1);

... and do some math from there.

Here's the odd part. If I use the sizeof() function inside the array, it returns a value of 4. I can use pointer notation to dereference the array:

int size = sizeof(*array1);

... but this actually returns a value of 8. This is odd, because the total size should be rows(which = 3) * columns(= 2) * sizeof(int)(= 4), or 24. And, indeed, this is the result, when I use sizeof(*array1) outside of the function.

Does anyone know what is going on here? More importantly, does anyone have a solution?

6 Answers
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