Question

When trying to create a category for NSInteger, the compiler complains that it “Cannot find interface declaration for ‘NSInteger'”. Is it not possible to create an NSInteger category?

A simple test will show the compiler error:

#import <Foundation/Foundation.h>

@interface NSInteger (NSInteger_Extensions)

-(NSInteger)simpleTest;

@end



#import "NSInteger_Extensions.h"

@implementation NSInteger (NSInteger_Extensions)

-(NSInteger)simpleTest {
    return self + 5;
}

@end

Should this be possible?

Thanks!

Answer 1

NSinteger is not an interface. So it’s not possible.

http://developer.apple.com/library/mac/#documentation/Cocoa/Reference/Foundation/Miscellaneous/Foundation_DataTypes/Reference/reference.html

From the link above:

Used to describe an integer.

#if __LP64__ || TARGET_OS_EMBEDDED || TARGET_OS_IPHONE || TARGET_OS_WIN32 || NS_BUILD_32_LIKE_64
typedef long NSInteger;
#else
typedef int NSInteger;
#endif

PS:
But you can make a category of NSNumber. I think it’s the thing you want to do