I am following a tutorial where using the UIPickerController to operate the camera. However when implementing UICollectionViewDatsaSource, I get an error saying that ViewController does not conform...

I'm getting a warning in Xcode 5 with the iOS 7 SDK that says Auto property synthesis will not synthesize property declared in a protocol I didn't get this warning in Xcode 4 with the iOS 6.1 SD...

I came across this code in ShareKit, and I don't understand what the writer had in mind, using self in a class method. There is a warning: Incompatible pointer types sending 'Class' to parameter ty...

Can anyone give example of forward declaration in objective C for a normal class and not for category or protocol?

Can anyone tell me what the angle brackets <...> in an Objective-C class interface do? Like this one (from http://snipt.net/robhawkes/cocoa-class-interface): @interface MapMeViewController : ...