Why does not set static variable?

Question

I have static variable:

static PaginationTableRestaurants *pagination;

After in implementation I do:

pagination.next = 3;
NSLog(@"%@", pagination.next);// nil

It gives me nil, why?

Where's the code that sets `pagination`? The only code you show doesn't set an initial value for `pagination`, just `pagination.next`. — rmaddy, Jan 14 '16 at 16:00
What is the data-type for 'next' in 'PaginationTableRestaurants' class ? — AskIOS, Jan 14 '16 at 16:13
Use an @property and read this: http://stackoverflow.com/questions/7026507/why-are-static-variables-considered-evil — emma ray, Jan 14 '16 at 16:23

Dare · Accepted Answer · 2016-01-14T16:26:04.440

You never initialized the pagination variable, judging by your code. If you try to set a property on a nil instance, your method call cannot work.

If it is actually important to you that that variable is static, you can achieve that behavior by getting it through a class method like this.

+ (NSArray *)restaurants
{
   static NSArray *_restaurants;
   static dispatch_once_t onceToken;
   dispatch_once(&onceToken, ^{
      _restaurants = @[
                  @"Restaurant 1",
                  @"Restaurant 2",
                  @"Restaurant 3",
                  @"Restaurant 4",
                  @"Options"
                  ];
   });
   return _restaurants;
}

The reality is that you almost certainly just want to declare a property and initialize it later.

@interface ViewController ()
@property (strong, nonatomic) NSArray *restaurants;
@end

Why does not set static variable?

1 Answers1