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Karan Khare
3,477 Pointsself & .
sometime we add "self" keyword to call and sometimes we add"_", why its so.
#import "UIViewController.h"
@interface ViewController : UIViewController
@property (strong, nonatomic) NSString *shoppingCart;
@property (strong, nonatomic) NSArray *shoppingList;
@end
#import "ViewController.h"
@implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
// Add your code below!
self.shoppingList = @[@"toothpaste",@"bread",@"eggs"];
}
@end
3 Answers
Patrick Cooney
12,216 PointsWhen you use self. you're calling the pre-built setter. It's the same as if you created a method like the following
-(void) setShoppingList:(NSArray *)list {
_shoppingList = list;
}
using self. is the safe way to do it because you're using the setter rather than directly changing the ivar value in memory. Basically under the hood Xcode is setting the ivar value for you though.
Karan Khare
3,477 Pointscan you please elaborate a little more with a better example. Help is much appreciated Thanks
Patrick Cooney
12,216 PointsThe best way I can describe it is _variable is accessing the value directly in the memory and self.variable is using the setter method. Maybe this post will help a bit more? (It's long but it might be just what you need).