Objective-C Category and new iVar

Question

I try to extend the functionality of SimpleAudioEngine of cocos2d with the ability to play several sound effect one after another as some kind of chain. I tried to do this w

Answer 1

You can not add iVars but can add property variables. Something like below:

In your .h:

#import 

@interface Chair (Liking)

     @property (nonatomic, assign)BOOL liked;
 @end

In your .m:

#import "Chair+ChairCat.h"

@implementation Chair (Liking)

 -(BOOL)liked{

    return [ objc_getAssociatedObject( self, "_aliked" ) boolValue ] ;    
 }

-(void)setLiked:(BOOL)b{    
    objc_setAssociatedObject(self, "_aliked",  [ NSNumber numberWithBool:b ],OBJC_ASSOCIATION_RETAIN_NONATOMIC ) ;

 }

@end

Then somewhere in some other class say myViewController.m

#import "Chair+ChairCat.h"
- (void)viewDidLoad {
    /////
    Chair *chair = [[Chair alloc] init];
    [chair setLiked:NO];
}