Different of the Asterisk * in Objective-C

Question

Currently, I'm starting an iphone application development. So, I have to retrieve my C knowledge back ( which wasn't good, got F twice back at the collage )

After I went to several tutorials and books, I notice something,

1. MyClass* myInstance
2. MyClass *myInstance
3. (MyClass *)myInstance

So far as I know, all of those are pointer (If I'm not misunderstanding). But what is the different between each of them. Or, they are just the same but define in different ways.

http://stackoverflow.com/questions/9393699/c-strings-and-pointers — ıllıllı lק ıllıllı, Feb 23 '12 at 08:20
possible duplicate of [Placement of the asterisk in Objective-C](http://stackoverflow.com/questions/1105815/placement-of-the-asterisk-in-objective-c) — jscs, Feb 23 '12 at 19:53

score 4 · Accepted Answer · edited May 23 '17 at 09:59

4

1, 2 no difference - depends on which style you prefer.

3 could be either a method declaration or the syntax for casting (thanks rob mayoff).

Method declaration: https://stackoverflow.com/a/683290/187954

Casting: https://stackoverflow.com/a/690760/187954

edited May 23 '17 at 09:59

Community

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answered Feb 23 '12 at 06:49

Michael Robinson

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#3 is also the syntax for casting. – rob mayoff Feb 23 '12 at 06:54
Thanks for the 1 and 2 clarification. But, does the 3rd one which is an input for a method are also mean it is a pointer too? – Tar_Tw45 Feb 23 '12 at 06:58
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Yes, it's a pointer. Objective-C objects are always passed by explicit reference (meaning, using a pointer), never by value. – rob mayoff Feb 23 '12 at 07:00
What about a sample method declaration in a link that you provided. "- (void) setPersonName: (char *)name andAge:(int)age andHeight:(float)height" .... name is definitely a pointer, what about age and height? – Tar_Tw45 Feb 23 '12 at 07:03
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They are not objects - they are primitive types. – Michael Robinson Feb 23 '12 at 07:03

Different of the Asterisk * in Objective-C

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