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iosobjective-ccocoa-touchpersistence

Xcode 4.3 Saving user data

I am making my first major iPhone app and need some advice in saving user data. I looking to save a complex multidimensional array for example a list of contacts with both general information and lists of more data.

I have been searching the internet for a long time and found many tutorials but they seem to be a bit vague or unclear.

What are the best practises in saving such data? If anyone can direct me to a good tutorial that would be great. It is critical that updating the app does not lose the saved data.

Thanks

Solution

  • NSUserDefaults doesn't lose data when you update.

    //Writing
[[NSUserDefaults standardUserDefaults] setInteger:1 forKey:@"anInt"];
[[NSUserDefaults standardUserDefaults] setDouble:1.2 forKey:@"aDouble"];
[[NSUserDefaults standardUserDefaults] setString:@"aString" forKey:@"aString"];
[[NSUserDefaults standardUserDefaults] synchronize];

//Reading:

int i = [[NSUserDefaults standardUserDefaults] integerForKey:@"anInt"]