Memory leak using NSMutableArray in RootViewController called from App Delegate

Question

I've written code to restore the state of my app, but there's a memory leak in the NSMutableArray. I'm new to Xcode so I apologize if this is something trivial I have overlooked. Any help is appreciated. lq

AppDelegate.m

- (void)applicationDidFinishLaunching:(UIApplication *)application {
    [rootViewController restoreState];
}

RootViewController.h

@interface rootViewController : UIViewController {
    NSMutableArray  *offendingNSMutableArray;
}
@property (nonatomic, retain) NSMutableArray *offendingNSMutableArray;

RootViewController.m

@synthesize offendingNSMutableArray;

- (void)restoreState {
    // Gets an array stored in the user defaults plist
    NSUserDefaults *userDefaults = [NSUserDefaults standardUserDefaults];
    self.offendingNSMutableArray = [[NSMutableArray alloc]    
            initWithArray:[userDefaults objectForKey:kArrayValue]];
}

- (void)viewDidUnload {
    self.offendingNSMutableArray = nil;
}

- (void)dealloc {
    [offendingNSMutableArray release];
}

Answer 1

If you set it to nil in viewDidUnload, what are you going to release in dealloc? You should just do

self.offendingNSMutableArray = nil;

in dealloc, that's the common way for retained properties.

EDIT: See it now from the comment above. You need autorelease where you do alloc/init. Property setter will do retain.

Answer 2

OK, so it looks like I solve the leak by adding autorelease:

- (void)restoreState {
    // Gets an array stored in the user defaults plist
    NSUserDefaults *userDefaults = [NSUserDefaults standardUserDefaults];
    self.offendingNSMutableArray = [[[NSMutableArray alloc]    
        initWithArray:[userDefaults objectForKey:kArrayValue]] autorelease];
}

But I thought I didn't want to use autorelease because I reference offendingNSMutableArray in other places in the app?