Objective-C

Objective-C: Any object can be nil, dynamic typing
Swift: Optionals can be nil, limited mutability
iOS Frameworks Design-Patterns: static typing

// Swift
override func viewWillAppear(animated: Bool){
	super.viewWillAppear(animated)
	displayResult()
}

// Objective-C
- (void)viewWillAppear:(BOOL) animated {
	[super viewWillAppear:animated];
	[self displayResult];
}

AppDelegate Methods

func application(application: UIApplication, didFinishLaunchingWithOptions
	launchOptions: [NSObject: AnyObject]?) -> Bool {
	return true
}
func applicationWillResignActive(application: UIApplication){
}
func applicationDidEnterBackground(application: UIApplication){
}
func applicationWillEnterForeground(application: UIApplication){
}

-(BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:
	(NSDictionary *)launchOptions {
	return YES;
}

- (void)applicationWillResignActive:(UIApplication *)application{
}

- (void)applicationDidEnterBackground:(UIApplication *)application {
}

- (void)applicationWillEnterForeground:(UIApplication *)application {
}