program received signal "EXC_BAD_ACCESS" - iphone

Question

When I run this following code it gives above error
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
self.window = [[[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]] autorelease];
[self.window makeKeyAndVisible];
self.viewController = [[ViewController alloc] initWithNibName:nil bundle:nil];
self.firstViewController=[[FirstViewController alloc]initWithNibName:nil bundle:nil];
UINavigationController *localNavigationController=[[UINavigationController alloc]initWithRootViewController:self.viewController];
self.navigationController=localNavigationController;
[localNavigationController release];
UINavigationController *localFistNavigationController=[[UINavigationController alloc]initWithRootViewController:self.firstViewController];
self.firstNavigationController=localFistNavigationController;
[localNavigationController release];
NSArray *twoBars=[[NSArray alloc]initWithObjects:self.navigationController,self.firstNavigationController, nil];
UITabBarController *localTAbBarController =[[UITabBarController alloc]init];
[localTAbBarController setViewControllers:twoBars];
self.tabBarController=localTAbBarController;
[localTAbBarController release];
[self.window addSubview:self.tabBarController.view];
return YES;
}
if i run following code it runs well
self.window = [[[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]] autorelease];
[self.window makeKeyAndVisible];
self.viewController = [[ViewController alloc] initWithNibName:nil bundle:nil];
self.firstViewController = [[FirstViewController alloc] initWithNibName:nil bundle:nil];
self.navigationController = [[UINavigationController alloc]
initWithRootViewController:self.viewController];
self.firstNavigationController=[[UINavigationController alloc]initWithRootViewController:self.firstViewController];
NSArray *twoBars=[[NSArray alloc]initWithObjects:self.navigationController,self.firstNavigationController, nil];
self.tabBarController=[[UITabBarController alloc]init];
[self.tabBarController setViewControllers:twoBars];
[self.window addSubview:self.tabBarController.view];
return YES;
i not understood what is the difference between these. in first one i just created local variables & assigned those to properties. in later one directly used the properties.
why it is giving the error- program recieved signal "EXC_BAD_ACCESS"

Answer 1

I think in first one you releases some code and then after release you again that object like:
[localTAbBarController release]; this. So may be thats why you got error- program recieved
signal "EXC_BAD_ACCESS". in second one you nicely use your object no releases so its work
fine.

Answer 2

UPDATE:
hey i use your code, here you get BAD_ACCESS on this bellow line see..
[localNavigationController release];
just comment it and you have not BAD_ACCESS

Answer 3

i got my answer. because of releasing same objects more than one time, it happens.
i have released [localNavigationController release]; two times. later it must be
[localFirstNavigationController release];

Answer 4

Just check this line.
self.firstNavigationController=localFistNavigationController;
-->> [localNavigationController release];
It should be [localFistNavigationController release];