If you want to store a small amount of information (e.g., user settings), whats the best, built-in way to go?

What are categories used for?

What is this a declaration of? int(^foo)(int);

What's the difference between an array and a set?

Dot notation can be used for _?

What is significant about this function declaration? -(void)testFunc:(NSString**)str;

How can you declare a method, that can be set as the action to be performed on various events?

What happens when you call retain on an object?

Developers are allowed to call [super dealloc] in ARC.

What is the difference between methods that begin with + and -?

What is KVO?