Question

I am a newbie to Objective C. What I am doing is setting some values in prepeareSegue for destination view controller. Strange thing is if I comment out NSLog in the function then value to destination controller’s property is not assigned.

My code for it is:

-(void) prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {

   if ([segue.identifier isEqualToString:@"ShowItemOnMap"] ) {
       LocateItemViewController *lic = [segue destinationViewController];
       NSIndexPath *index = [self.tableView indexPathForSelectedRow];

       // self.itemsToBuy is a array of NSDictionary
       NSDictionary *selectedItem = [self.itemsToBuy objectAtIndex:[index row]];
       Item *theItem = [[Item alloc] init];
       NSString *theTitle = [[NSString alloc] initWithString:[selectedItem valueForKey:@"title"]];
       theItem.title = theTitle;
       lic.item = theItem;

       // commenting out NSLog make self.irem in LocateItemViewController nil
       // and no value is shown at screen
       NSLog(@"%@", lic.item.title);
   }

}

Item is a custom class with property

@property (strong, nonatomic) NSString *title;

LocateItemController has following properties

@property (weak, nonatomic) Item *item;
@property (strong, nonatomic) IBOutlet UILabel *titleLabel;

and viewDidLoad simply assigns item

self.titleLabel.text = self.item.title;

Answer 1

If you need item to be retained, you should make it a strong property.