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iOS Build a Simple iPhone App with Objective-C Creating a Data Model Creating a Data Collection

Posted by Jérémy Brunet
Jérémy Brunet
2,014 Points

Why using "self" when we initialize an NSArray?

I can't get through this challenge's second step when I'm asking to set the NSArray "shoppingList" with 3 elements. I'd have written shoppingList = [[NSArray alloc] initWithObjects:@"toothpaste", @"bread", @"eggs"] but it keeps prompting that I need to use "self.shoppingList"? Why and what's the right chunk of code then?

ViewController.h 
#import "UIViewController.h"

@interface ViewController : UIViewController

@property (strong, nonatomic) NSString *shoppingCart;
@property (strong, nonatomic) NSArray *shoppingList;
@end
ViewController.m 
#import "ViewController.h"

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];

    // Add your code below!
  shoppingList = [[NSArray alloc] initWithObjects:@"toothpaste", @"bread", @"eggs"];

@end

1 Answer

Jérémy Brunet
Jérémy Brunet
2,014 Points

I've just figured it out... You have to add self to shoppingList and also nil as the last element of the array. Clicking the Preview button to read the output has been very useful, but tips don't help at all.

For the next step, don't forget the underscore when calling shoppingList.