Question

Here are two methods in a view controller from an Apple tutorial:

- (void)viewDidUnload {
    self.eventsArray = nil;
    self.locationManager = nil;
    self.addButton = nil;
}

- (void)dealloc {
    [managedObjectContext release];
    [eventsArray release];
    [locationManager release];
    [addButton release];
    [super dealloc];
}

Couldn’t the dealloc method be shortened to the following? If not, why not?

- (void)dealloc {
    [managedObjectContext release];
    [super dealloc];
}

Answer 1

- (void)viewDidUnload is not guaranteed to be called, so you should always release things in dealloc too.

See this question to find out when it’s called, and what you should do when it is.