Question

I want to save some integers after application shut down and restore them after application opening, what is the easiest way to do this?

Answer 1

You should store and load data from NSUserDefaults:

http://developer.apple.com/library/IOS/#documentation/Cocoa/Reference/Foundation/Classes/NSUserDefaults_Class/Reference/Reference.html

NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
// to store
[defaults setObject:[NSNumber numberWithInt:12345] forKey:@"myKey"];
[defaults synchronize];

// to load
NSNumber *aNumber = [defaults objectForKey:@"myKey"];
NSInteger anInt = [aNumber intValue];