Returning a pointer

Discussion in 'Mac Programming' started by jwei92, Jun 5, 2011.

  1. macrumors newbie

    Jun 5, 2011
    I've looked through a couple threads and am still lost on returning pointers.

    I am currently in the process of learning Obj-C with not previous programming background.

    I know some basics, but the only thing I cannot seem to grasp is in Kochan's Objective-C 2.0's book (Chapter 8 - A Point Class and Memory Allocation)

    I know how to allocate, but here are the parts that confuse me:

    @interface Rectangle:NSObject 
        int width, height;
        [I]XYPoint *origin;[/I]
    I do not understand why the method returns pointers and such. Sorry if my question isn't clear, but can someone elaborate on why you return a pointer and not just an integer?
  2. macrumors 68040


    Jan 10, 2005
    Dallas, TX
    All objects are gotten to in Objective-C via a pointer. That's it. Passing an object? You pass a pointer. Getting one back? Pointer. End of story. If it's just an int, sure... just return the int. There may be some reason to return a pointer to a primitive (maybe you want to modify it and have that affect something else that also uses the value in that memory location), but with objects there is no question.

  3. macrumors 68000

    Sep 8, 2006
    That was the point I got to in that same book. When he started in with pointers and self it got complicated. I then put that book down and Thought, Objective C is built on top of C. So I got the book "Learn C on the Mac" and that book was pretty easy to follow, this was end of last year.

    I have now started back on learning Objective C and from the C book I understand all of the pointer concepts, data structures , functions and so on. Since I liked the Aprees book Learn C on the Mac I decided to start with Learn Objective C for Absolute Beginners by the same company. I just started reading it the other day.

    If it gets hard for you, like me, then I recommend taking it a step back to something simpler. This is from experience.

  4. macrumors 6502

    Jan 13, 2011
    Los Angeles, CA
    +1 These are the books I started with. They are much easier to digest than Kochan's book. Kochan's book is a great 3rd book to read.

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