KVO vs NSNotification vs protocol/delegates?

Question

I have some idea of which to use when but the exact usage is still not clear to me. Can someone explain with example?

Answer 1

Even when all three would serve your need in a situation, delegate would still be a prefer option:

1. Reuseability.
2. Self documented. By examining the class's header file, one would immediately recognize what / how the data exchanged taking places.