Question

in my viewDidLoad, I add my controller as an observer for two notifications:

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(checkNetworkStatus:) name:NetworkStatusChangedNotification object:nil];
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(checkLocationStatus:) name:LocationStatusChangedNotification object:nil];

in my dealloc, should I remove it once, or twice? The removeObserver method doesn’t seem to specify a particular notification.

[[NSNotificationCenter defaultCenter] removeObserver:self];
[[NSNotificationCenter defaultCenter] removeObserver:self]; // is this required?

Answer 1

You need to remove it only once.

If you need it, you can also use -removeObserver:name:object: to stop observing just one of the notifications.