What happens at runtime with the following: NSMutableString *tempString = [NSMutableString stringWithString:@"1"]; dispatch_sync(dispatch_get_main_queue(), ^{ [tempString appendString:@"2"]; NSLog(@"%@", tempString); }); [tempString appendString:@"3"];

What happens if two categories define methods with the same names for the same class?

What сan you use to avoid msgSend function overhead?

Which of the following statements is correct?

Why should you use an autorelease pool ?

A class can have two methods with the same name, but with different argument types.

What happens when the following code executes?

Which one is correct (legal) floating-point literal ?

A derived class can access all the private members of its base class if it's defined in the interface class

In Objective-C, retain counts are the way in which memory is managed in Objective-C

The (...) method can be used to see if an object belongs to a class that implements a particular protocol.