|Mar 26, 2008, 12:01 PM||#1|
Why no * under polymorphism for superclass?
Hello. Need some help from the ObjC pros.
SpecificA *spec1 = [SpecificA new];
SpecificB *spec2 = [SpecificB new];
generalData = spec1;
generalData = spec2;
QUESTION: Why is it not
missing the dereferencing operator *???
Aren't all objects in ObjC really just pointers to struts? And therefore, the id "superclass" type should have generalData declared as a pointer, no?
|Mar 26, 2008, 12:28 PM||#2|
Go outside, the graphics are amazing!
|Mar 26, 2008, 12:39 PM||#3|
Thanks! Phew. You have no idea how much you helped clear up. It is really confusing for a beginner.
You are right, it should have been implemented to be declared specifically. After all, a lot of the syntax is supposed to force us to be clear about things and for the compiler to help check stuff at compile time.
I wonder if I can still use * without a compiler error? (Will try it later with gcc).
Actually, do you (or anyone else) have any general guideline about when to use * and when not to? (I still have not grokked a "golden rule" yet about this).
I know about using * to dereference, etc. a-la standard C; I am just sometimes confused why we use * and sometimes not, when dealing with objects.
I figured that anything inside the [brackets] is ObjC helping to "pre-process" the OOP stuff, so we don't use * inside the brackets, but outside of them, it sometimes gets confusing since there seem to exceptions to rules (as in the abovementioned original problem I had).
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