Which method, if defined, is guaranteed to be called once -- and only once -- when a class is first referenced?

What do you use for an outgoing TCP connection?

What class method is used to make an NSArray from NSData class?

What happens at runtime with the following: dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0); dispatch_apply(10, queue, ^(size_t index) { NSLog(@"%zu", index); });

What can you say about the code: NSString * str = [NSString stringWithFormat:@""]; [str release];

What is the last chance for an object to handle a message?

Which one contain an INCORRECT way to declare and initialize an array ?

In Objective-C, sometime, you may find that you wish to extend an existing class by adding behavior that is useful only in certain situations. In order to add such extension to existing classes, Objective-C provides ...

The (...) is an Objective-C directive, which is also used to define the aliases for various data types similar to (...). But (...) is limited to giving symbolic names to types only, whereas (...) can be used to define alias for values as well, like you can define 1 as ONE, etc.

Which one contains an INCORRECT concept regarding Objective-C programming ?

Which one is NOT correct regarding memory management in Objective-C ?