Add 'addObserver' (NSNotificationCenter ) in a 1st view controller, handle in 2nd [duplicate]

Answer 1

There is another way to do this (in case you want to let other view controllers know if a value of an object has changed). You can use KVO (Key-Value Observing): http://developer.apple.com/library/ios/#documentation/cocoa/conceptual/KeyValueObserving/Articles/KVOBasics.html