iPhone: can you tell me the difference b/t (NSObject *)obj&(NSObject *obj)

Can you tell开发者_运维百科 me what the difference is between -(NSObject *)obj and -(NSObject *obj)?

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-(NSObject *)obj is the signature of an instance method called obj that returns a pointer to an NSObject.

-(NSObject *obj) is nonsense.

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(type)obj tells the code that you have an object "obj" and it is of type "type"

(type *)obj tells the code that you have a pointer to an object "obj" and it is of type "type"

Examples:

(int)n means I'm giving you an integer called n (float)n means I'm giving you a float called n

(NSObject *)obj means I'm giving you a pointer to an NSObject called obj

Non-Examples:

(int n) or (float n) or (NSObject *obj) are all nonsense

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The first is a cast (NSObject *)obj whilst the second is a (NSObject *obj) dispensable use of brackets