macOS Setting NSNumber

[larswik]

-(IBAction)itemPhotoSwapBut:(id)sender{ 
    NSInteger tag = [sender tag];
    NSArray *photoNumArray = @[photo1selected,photo2selected,photo3selected,photo4selected]; // array of global NSNumbers instantiated to 0
    butImageCounter = 0;
   [[photoNumArray objectAtIndex:tag]setIntValue:butImageCounter];
}

Error

[__NSCFNumber setIntValue:]: unrecognized selector sent to instance 0x27

I seem to be struggling with this. I have 4 NSNumber objects in the header. in my awakeFromNib I assign them all to an int value of 0. I have 4 NSButtons assigned to this one method and use the [sender tag] to identify which button is pushed. In the example above I am trying to store the int value of 0 but I am getting this crash error. The error seems to indicate it is no longer in memory?

 

[Sydde]

NSNumber is immutable. If you want to change the value it holds, you must discard the object and re-init a different one.

 

[larswik]

NSNumber is immutable. If you want to change the value it holds, you must discard the object and re-init a different one.

A quick web search confirmed it is not mutable. I did't think to even look at that as an answer to my problem. Thanks. From my experience that error message means the object does not exists.

 

[Sydde]

The reason you are seeing that odd 0x27 pointer is because there are some factory-like instances of NSNumber for the common values like zero or seven or whatever. All four of your numbers that you initialized to 0 will be the same object.

Really, if you are not encoding the value or putting it in an array, just use a NSInteger primitive.