Apple QA1758: Prior to iOS 6 / OS X 10.8, using the the Zombies instrument or NSZombieEnabled or the “Enable Zombie Objects” Xcode diagnostic, prevented ARC from “cleaning up” instance variables at deallocation-time. Your -dealloc methods would still be run, however any instance variables that you didn’t explicitly set to nil would be untouched. If … Continue reading Zombies and ARC