Objective-C quiz

Test your Objective-C knowledge with a free interactive quiz — 42 questions with answers and explanations. No signup needed to play.

Which of these correctly declares a mutable copy of an NSString?

1. Which of these correctly declares a mutable copy of an NSString?
2. What is the correct syntax for calling a method on an object in Objective-C?
3. What does `@synthesize` do (when it was still commonly written explicitly)?
4. What is the difference between `strong` and `weak` property attributes?
5. What does `nil` mean in Objective-C, and what happens when you send a message to it?
6. What is a "selector" in Objective-C?
7. What is the difference between `NSArray` and `NSMutableArray`?
8. What is the correct way to check if an object conforms to a protocol at runtime?
9. What is a block in Objective-C?
10. What is `NSDictionary` used for?
11. What does `@protocol` define?
12. What are the two required file types for a typical Objective-C class?

More quizzes