AppDelegate Method - Store a Variable (Singleton)

AppDelegate.h :

#import <UIKit/UIKit.h>

@interface AppDelegate : UIResponder <UIApplicationDelegate>

{

 NSString *name;

}

@property(strong,nonatomic)NSString *name;

@end

AppDelegate.m :
 //Nothing Do

SomeFile.h :

#import "AppDelegate.h"

@interface SomeFile : UIViewController

{

    

}

-(IBAction)save:(id)sender;

-(IBAction)retrive:(id)sender;

@end

SomeFile.m :
-(IBAction)save:(id)sender
{
      AppDelegate *del=(AppDelegate *)[[UIApplication sharedApplication]delegate];
      [del setName:txt_name.text];
}

-(IBAction)retrive:(id)sender
{
      AppDelegate *del=(AppDelegate *)[[UIApplication sharedApplication]delegate];
     if (del.name==nil)

     {

           // Login page is showed

     }

     else

     {

           NSString *name = del.name; 

     }

}