What is a dependency in NSOperationQueue?

What is the Allocations instrument used for?

What is KVO?

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

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

What happens when you call retain on an object?

You are worried about threaded access to a property and possible collision in writing. What directive should you use on the property?

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

Dot notation can be used for _?

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

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