What should my Objective-C singleton look like? [closed]

Answer 1

For an in-depth discussion of the singleton pattern in Objective-C, look here:

Using the Singleton Pattern in Objective-C

Answer 2

Just wanted to leave this here so I don't lose it. The advantage to this one is that it's usable in InterfaceBuilder, which is a HUGE advantage. This is taken from another question that I asked:

static Server *instance;

+ (Server *)instance { return instance; }

+ (id)hiddenAlloc
{
    return [super alloc];
}

+ (id)alloc
{
    return [[self instance] retain];
}


+ (void)initialize
{
    static BOOL initialized = NO;
    if(!initialized)
    {
        initialized = YES;
        instance = [[Server hiddenAlloc] init];
    }
}

- (id) init
{
    if (instance)
        return self;
    self = [super init];
    if (self != nil) {
        // whatever
    }
    return self;
}