Question

How can I use key-value coding messages (setValue:ForKey: and so on) with id type? Key-value coding protocol is implemented as an informal protocol, so it is not included in <NSObject> protocol and I can’t simply say id<NSObject> setValue:ForKey:.

Answer 1

Just call the method. The compiler won’t emit warnings for unknown methods on id variables.

id myObj = [myArray objectAtIndex:0];
[myObj setValue:@"value" forKey:@"key"];