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Pablo Cornejo
10,404 PointsWhat's the importance of de-registering the class from being an observer?
In the video, Pasan wrote the code to set up the UIViewController class as an observer of a certain notification. Then he ran the app and everything worked normally.
Finally, he said that we need to de-register the class from the observer list in NotificationCenter, and he did so in the deinit{} method.
As the app did run normally without this last step, I didn't really get the importance of de-registering the class as an observer.
Why is it important to do this and what are the consequences if this is not done?
1 Answer
David Lin
35,864 PointsYou no longer need to de-register in iOS9.
In iOS8 and prior, if you didin't de-register in the destructor, the notification center would keep sending notifications to a no-longer existing object, thus crashing the app.