Question

Hi I’m studying IOS programing through example code from the web. I found that something is weird from this code because they already have h.file but they also have h.file code inside of the m.file as well.

 @interface Manager : NSObject {
}

+(void) goMenu;

this is h. file

#import "Manager.h"

@interface Manager ()
+(void) go
+(void) wrap
@end


@implementation Manager
....

and this is beginning of m.file.

For beginner like me, this kind of situation making me really confusing. Please someone explain me what is happening?

Answer 1

@interface Manager () in the implementation file is known as a class extension.

This is often used to add methods, properties etc. that the developer wants to keep private.