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Just a general question regarding the difference between extending a class and implementing it.
@interface AppDelegate : UIResponder <UIApplicationDelegate>
In my example my class AppDelegate extends from the UIResponder Class but implements the UIApplicationDelegate class.
Can somebody please explain… Do you have also possibilities to access methods of the UIApplicationDelegate object/ class? Where are the differences?
Thanks
If you are speaking in Java terms, then in your example you are Extending (generally referred to as Subclassing) the UIResponder class.
Your example is also implementing the UIApplicationDelegate which is similar to implementing an Interface where you have to define the required methods of the UIApplicationDelegate Protocol and you have the option of implementing the optional methods.
Similar to Java, you can only extend or subclass one class but you can implement multiple delegate protocols in your class
Apple’s guide to Protocols is very handy if you want to understand more: https://developer.apple.com/library/mac/#documentation/Cocoa/Conceptual/ObjectiveC/Chapters/ocProtocols.html