// Header File that provides all UI related items. 
#import <UIKit/UIKit.h> 
 // Forward declaration (Used when class will be defined /imported in future)
@class ViewController;  

// Interface for Appdelegate
@interface AppDelegate : UIResponder <UIApplicationDelegate>
// Property window
@property (strong, nonatomic) UIWindow *window;
// Property Viewcontroller
@property (strong, nonatomic) ViewController *viewController;
//this marks end of interface
@end

// Imports the class Appdelegate's interface
import "AppDelegate.h" 

// Imports the viewcontroller to be loaded
#import "ViewController.h"

// Class definition starts here
@implementation AppDelegate

// Following method intimates us the application launched successfully
- (BOOL)application:(UIApplication *)application
didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
self.window = [[UIWindow alloc] initWithFrame:
[[UIScreen mainScreen] bounds]];
// Override yiibai for customization after application launch.
self.viewController = [[ViewController alloc]
initWithNibName:@"ViewController" bundle:nil];
self.window.rootViewController = self.viewController;
[self.window makeKeyAndVisible];
return YES;
}

- (void)applicationWillResignActive:(UIApplication *)application
{
/* Sent when the application is about to move from active to inactive state.
This can occur for certain types of temporary interruptions
(such as an incoming phone call or SMS message)
or when the user quits the application and it begins the transition to the
background state. Use this method to pause ongoing tasks, disable timers,
and throttle down OpenGL ES frame rates. Games should use this method
to pause the game.*/
}

- (void)applicationDidEnterBackground:(UIApplication *)application
{
/* Use this method to release shared resources, save user data, invalidate
timers, and store enough application state information to restore your
application to its current state in case it is terminated later. If your
application supports background execution, this method is called instead
of applicationWillTerminate: when the user quits.*/
}

- (void)applicationWillEnterForeground:(UIApplication *)application
{
/* Called as part of the transition from the background to the inactive state;
here you can undo many of the changes made on entering the background.*/
}

- (void)applicationDidBecomeActive:(UIApplication *)application
{
/* Restart any tasks that were paused (or not yet started) while the
application was inactive. If the application was previously in the background,
optionally refresh the user interface.*/
}

- (void)applicationWillTerminate:(UIApplication *)application
{
/* Called when the application is about to terminate. Save data if appropriate.
See also applicationDidEnterBackground:. */
}

@end

#import  

// Interface for class ViewController
@interface ViewController : UIViewController

@end

#import "ViewController.h"

// Category, an extension of ViewController class
@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
}

- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}

@end