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iOS

Posted by Megha Makode
Megha Makode
1,079 Points

Assign an Array Object to a NSString

Hey All:-),

Challenge #We're at the grocery store shopping and we found the eggs. In the header file we have a property, shoppingCart, of type NSString. In the viewDidLoad method, retrieve the string eggs from the shoppingList array and store it in shoppingCart. Hint: use the 'objectAtIndex' method.

#import "ViewController.h"

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    self.shoppingList = [[NSArray alloc] initWithObjects: @"toothpaste", @"bread", @"eggs", nil];
    self.shoppingCart = *shoppingList.objectAtIndex:2 ;
}

@end

I'hv tried this challenge like 100 different ways and once i even got it right and moved on to next video but i don't remember what did i do!

so could anyone please tell me how to assign an array object to a NSString?

Thnx In Advance:-)

3 Answers

Safwat Shenouda
Safwat Shenouda
12,362 Points
Safwat Shenouda
Safwat Shenouda
12,362 Points

You need to use NSMutableArray for shoppingCart , so you can add objects to it. then you can add objects of as follows: ''' self.shoppingCart= [NSMutableArray alloc]; [self.shoppingCart addObject:[self.shoppingList objectAtIndex:2]]; ''' /// Another thing, you need to have a pointer to a NSString to be able to assign an object to it, offcourse that object should be of type NSString as well. so first define @property NSString* mystring; in your header. then assign object to it the same way like above: mystring = [self.shoppingList objectAtIndex:2];

Megha Makode
Megha Makode
1,079 Points
Megha Makode
Megha Makode
1,079 Points

Thnx So much Safwat for replying so promptly:-) actually it was specified to create an NSArray only by name shoppingList and then retrieve its 3rd element "eggs" and assign it to an empty NSString named shoppingCart. I tried it further and I got it right this way:

self.shoppingCart = [_shoppingList objectAtIndex:2];

instead of 

self.shoppingCart = [*shoppingList objectAtIndex:2];

Or

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

I tried that underscore in front of Arrayname only when editor suggested it, so m still kinda confused about how it worked... Seems like we could put underscore in front of ArrayName as well instead of self. or *. Is it?

Safwat Shenouda
Safwat Shenouda
12,362 Points

You are welcome :)

I'm not sure about the impact of using _ , but for sure you should not use *

Megha Makode
Megha Makode
1,079 Points
Megha Makode
Megha Makode
1,079 Points

:-) Oh Okay