Question

Here is the function I have, “Sprite” is an object in the program, and “GetSpriteAtPosition” just returns a pointer to the correct sprite at the coordinates.

My problem is that I store a letter in each sprite, in the form of an integer. 0 is a, and 25 is z, with everything in between respectively. I need my function to return a char* that gives me the letters of a row of sprites, so if in the program the sprites spell out “abcdefgh”, then that’s what I need this function to print out. There’s an 8×8 grid of sprites, and I’m getting the coordinates correctly, but I get an error that I can’t convert an int to a char* in the marked line. What can I do to get this to work?

Thanks in advance!

char* RowLetters(int row)
{
    char* pointer;
    for( int i = 0; i < 8; i++)
    {
        Sprite* selectedSprite = SpriteAtPosition(row*50, i * 50);
        if(selectedSprite != NULL)
        {
            char* temp = (char)(selectedSprite->Frame() + 97); //error here
            pointer = strcat(pointer, temp);
        }
        else
        {
            pointer = strcat(pointer, "test");
        }
    }
    return pointer;
}

Answer 1

Try this:

        char temp = (char)(selectedSprite->Frame() + 97);
        pointer = strcat(pointer, &temp);

I’ve changed the variable into a standard char rather than a pointer and then passed a reference to strcat() with the & operator.

EDIT:

As pointed out in the comments, this doesn’t work because &temp isn’t NULL terminated. I used to get around this when I programmed more C by doing the following.

        char temp[2];
        temp[0] = (char)(selectedSprite->Frame() + 97);
        temp[1] = '\0';
        pointer = strcat(pointer, temp);

Of course, the temp array could be declared outside the for() loop for a little better performance (in theory).

None of this addresses the other problems with the code like pointer never being declared. I think a broader understanding of the calling function would be in order to determine whether pointer should be allocated within this function or passed in by the caller.