2D Arrays in Objective C

Question

I have a collection of NSObjects that I want to store in a 2D array generated at run time. In C# I'd just be using some of their friendly generic containers, but not too sure the best way to go about it in objective-c for iphone development.

I'm guessing that NSMutableArray isn't the best route. I don't need the array to grow, I'll know the size I want when my grid manager is created, but the grid will be constructing with a runtime height and width.

Should I be doing something along the lines of 'NSObject** gridObjects = alloc...'?

Answer 1

If you are going to store POINTERS in your 2D array, you will have to use:

NSObject ***gridObjects

I would just use a NSArray of NSArray objects (2D).

Answer 2

You can always use plain C stuff in Objective-C (I wouldn't suggest doing this unless you have good reasons to):

NSObject** *twoDArray = malloc(sizeof(NSObject**) * rows);
for (i = 0; i < rows; ++i)
    twoDArray[i] = malloc(sizeof(NSObject*) * cols);

To resize each block, you can use realloc (if you even needed). Don't forget to free after use.