Objective-c get last 2 characters of string?

Question

Let's say I have a line:

NSString *state = @"California, CA"; 

Can someone tell me how to extract the last two characters from this line (@ "CA" in this example)

Answer 1

 NSString *code = [state substringFromIndex: [state length] - 2]; 

gotta do it

Answer 2

Swift 4:

 let code = (state as? NSString)?.substring(from: state.characters.count - 2)