NSNotificationCenter: Why bother calling removeObserver?

Question

The gods have parachuted many habits into my isolated jungle village, such as:

- (void) dealloc {

  [[NSNotificationCenter defaultCenter] removeObserver:sel         


        

Answer 1

NSNotificationCenter doesn't retain observers. If you don't remove the observer, and the observer is deallocated, then NSNotificationCenter is left holding a dangling pointer which will (most often) crash when it next tries to notify the observer.