Question

I am a new programmer and have searched for this answer, but think I might not be using the right terminology.

What I am trying to do is allow the user to use my application, which is a game, only once in a 24 hour period. If they try to play the game earlier than the 24 hour period, I would like an alert that tells them to come back later. I have seen this done for other games that give you “credits”, but can’t seem to find the code.

Any help is appreciated!

Answer 1

Use the NSDate class to get the current date ([NSDate date]), and then save this value using the NSUserDefaults class. When the app is opened, retrieve the value and then compare the old date with the current date. If it has been a day, don’t do anything. Otherwise, show an alert.

//setting the date
[[NSUserDefaults standardUserDefaults] setObject:[NSDate date] forKey:@"Date"];

//retrieve date
NSDate *date = [[NSUserDefaults standardUserDefaults] objectForKey:@"Date"];

//now compare the dates