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Sean Craig
5,178 PointsIm struggling with how to initialize the array for the grocery shopping list.
I cant figure out what I'm doing wrong trying to initialize the array.
#import "UIViewController.h"
@interface ViewController : UIViewController
@property (strong, nonatomic) NSArray *shoppingList;
@end
#import "ViewController.h"
@implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
// Add your code below!
NSArray *shoppingList = [[NSArray alloc] initWithObjects:@"toothpaste", @"bread", @"eggs", nil];
}
@end
4 Answers
Stepan Ulyanin
11,318 PointsHi! First of all you already have the shoppingList property declared in the interface of the controller, so in your implementation it would be something like:
- (void)viewDidLoad {
[super viewDidLoad];
// Add your code below!
self.shoppingList = [[NSArray alloc] initWithObjects:@"toothpaste", @"bread", @"eggs", nil];
}
Other than that, the array initialization seems fine!
Caleb Kleveter
Treehouse Moderator 37,862 PointsI'm not quite sure what you mean.
Stepan Ulyanin
11,318 PointsAccording to the apple reference:
Although it’s best practice for an object to access its own properties using accessor methods or dot syntax, it’s possible to access the instance variable directly from any of the instance methods in a class implementation. The underscore prefix makes it clear that you’re accessing an instance variable rather than, for example, a local variable.
When you use the _variable, it is the instance variable and it is not recommended to access it directly unless you have the real reason to
Caleb Kleveter
Treehouse Moderator 37,862 PointsInteresting, good to know.
Mahesh Babu
3,402 PointsHi,
You have declared a property of type shoppingList, so all you have to do is use _ shoppingList variable, but i would definitely recommend self.shoppingList as that is the standard syntax unless you are using an initializer , you should not use the _shoppingList.
I would definitely let the standard syntax go off the box and do the literal syntax nice and clean,
self.shoppingList = @[@"toothpaste", @"breads",@"eggs"];
Caleb Kleveter
Treehouse Moderator 37,862 PointsTry this:
_shoppingList = [[NSArray alloc] initWithObjects:@"toothpaste", @"bread", @"eggs", nil];
Stepan Ulyanin
11,318 PointsWhy would you mess up with the instance variable in this case? I mean isn't it a bad practice to mess around with the instance variable unless you are writing the initialization method?