ios - How to share data between ViewControllers in a tabbed application

Question

I want to share a variable between a few ViewControllers in a tabbed application. I tried using the [NSUserDefaults] to save and load the variables but the application crashes each time. Here is my code in the SecondViewController

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

        totalApples = [[NSUserDefaults standardUserDefaults]integerForKey:@"numberOfApples"];
        [self setText:[NSString stringWithFormat:@"%g", totalApples] withExistingAttributesInLabel:self.l1];

    }

It highlights the [super viewDidLoad]; when I click on the tab to open the second view as the cause of the crash.

Answer 1

Just in case : if you just need to share data between several VCs, NSUserDefaults may not be the best way for your Model. In that case, you may want to consider creating a class where the shared data is located, using the benefits of the singleton design pattern.