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iOS

Posted by Joshua Cawthorne
Joshua Cawthorne
1,742 Points

Build a Simple iPhone App w/ Objective-C -- Data Collection Code challenge Task #3

Having trouble with this skills test that I feel should be working. I’ve tried several ways to do this however; the error generator is saying I should be using _shoppingCart and _shoppingList. It is my understanding that the _someVariable is used only when variables have been synthesized.

The tutorial hasn’t covered this yet, neither does it accept the following answers I tried providing. I believe I did it exactly the way the tutorial just covered and below are just two of the many attempts, including initializing the string variable.

Thanks,

CURRENT code:

Bummer! Remember array indexes start at zero. Access the third item in the array and assign it to a string named `shoppingCart`.

#import "ViewController.h"

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];

  self.shoppingList = [[NSArray alloc] initWithObjects: @"toothpaste", @"bread", @"eggs", nil];

  self.shoppingCart.text = [shoppingList objectAtIndex: 2];
}

@end

//WITH _variable
#import "ViewController.h"

@implementation ViewController

- (void)viewDidLoad {
   [super viewDidLoad];

 _shoppingList = [[NSArray alloc] initWithObjects: @"toothpaste", @"bread", @"eggs", nil];

 _shoppingCart.text = [_shoppingList objectAtIndex: 2];
}

@end


//WITHOUT _variable
#import "ViewController.h"

@implementation ViewController

- (void)viewDidLoad {
   [super viewDidLoad];

 self.shoppingList = [[NSArray alloc] initWithObjects: @"toothpaste", @"bread", @"eggs", nil];

 self.shoppingCart.text = [shoppingList objectAtIndex: 2];
}

@end
Joshua Cawthorne
Joshua Cawthorne
1,742 Points

As a note, I also tried [self.shoppingList objectAtIndex: 2]; also. I also was incorrect that the synthesizing I believe is for backwards compatibility of older iOS versions. The _ is for the actual memory location of the variable if Im saying this right.

2 Answers

Radoslav Radev
Radoslav Radev
4,732 Points
Radoslav Radev
Radoslav Radev
4,732 Points 
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!
     self.shoppingList = [[NSArray alloc] initWithObjects:@"toothpaste",@"bread",@"eggs", nil];
     self.shoppingCart = [_shoppingList objectAtIndex:2];
}

@end
Caleb Kleveter
MOD
Caleb Kleveter
Treehouse Moderator 37,862 Points
Caleb Kleveter
Caleb Kleveter
Treehouse Moderator 37,862 Points

Take a look at this thread, it might help you find the answer.