Class level attributes in Objective-C (remove warning)

Question

Hi,

I've read somewhere that Objective-C doesn't have class level attributes, but that the same can be achieved by declaring something like this (before the class interface):

static NSInteger initCount;

I'm initializing the variable to zero with the initialize method:

// interface
+ (void) initialize;

// implementation
+ (void) initialize {
   initCount = 0;
}

And incrementing/decrementing when an instance is created/dealloc'd:

- (id) init {
    self = [super init];

    initCount++;

    return self;
}

- (void) dealloc {
    [name release];

    initCount--;

    [super dealloc];
}

But XCode keeps warning me that "'initCount' defined but not used".

Is there any way to solve this, or should I just ignore the warning?

Answer 1

Do you also have an instance variable named "initCount"? If so, you're referencing this in your init/dealloc methods, and not the global.

Answer 2

It should go in your implementation file, not your interface. If you put it in your header, a separate variable called initCount will be created in each file that imports the header (because a static variable has file scope, and #import textually inserts the contents of the header).