Cocoa quiz

Test your Cocoa knowledge with a free interactive quiz — 24 questions with answers and explanations. No signup needed to play.

What does `NSCopying` conformance provide, and why does it matter for value-like Cocoa objects?

1. What does `NSCopying` conformance provide, and why does it matter for value-like Cocoa objects?
2. What is `NSCache` and how does it differ from a plain `NSMutableDictionary` used as a cache?
3. What role does `Info.plist` play in a Cocoa app?
4. What is the role of `NSObject` in Cocoa?
5. What is the difference between Foundation and AppKit/UIKit in the Cocoa stack?
6. What is Key-Value Observing (KVO) and how does it relate to KVC?
7. What is a "weak" vs a "strong" IBOutlet, and which is generally recommended for a view already retained by its superview's hierarchy?
8. What is the difference between the app delegate (`UIApplicationDelegate`/`NSApplicationDelegate`) and a `SceneDelegate` in a modern iOS app?
9. What is the purpose of `NSOperation`/`NSOperationQueue` relative to Grand Central Dispatch (GCD)?
10. What is a "singleton" pattern usage in Cocoa, and what is a well-known built-in example?
11. What is the target-action pattern used for in Cocoa UI controls?
12. What is Cocoa in the context of Apple platform development?

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