How do I display an integer from an NSArray on a UILabel?

Question

I realize this is a dumb beginner question, but I have been stuck for at least an hour on trying to get an integer value from my array to display on a label when I press a button. The problem is that the label keeps displaying "(null)" no matter what index I put the label to look at. I have tried taking out the quotation marks on the NSArray objects too. It doesn't matter too much whether the objects within the NSArray are integers or strings, but I would at least like to know the syntax on how to put them into the array because I believe that's my problem. If not, show me otherwise please.

My code: (.h file)

@property (strong, nonatomic) NSArray *redOneTeams;

(.m file)

    - (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
        // Custom initialization
        _redOneTeams = @[
                   @"4351",
                   @"4298",
                   ];
        }
    return self;
}

- (IBAction)saveBtn:(id)sender {
    _teamNumber.text = [[NSString alloc] initWithFormat: @"%@", [_redOneTeams objectAtIndex:0]];
}

How is this view controller being created? Break this problem into two parts by just saying `_teamNumber.text = @"works!"` in your `saveBtn:`. Then we know if the issue is the array or your outlet to the label. — Firoze Lafeer, Mar 05 '13 at 03:53
I have like 30 other labels in my app that work when displaying NSIntegers, I'm just trying to get this specific one to work. — Louie Bertoncin, Mar 05 '13 at 04:01

score 0 · Answer 1 · answered Mar 05 '13 at 03:54

So there are a couple of options here:

1- Put the numbers directly into your array as numbers:

_redOneTeams = @[
               @4351,
               @4298,
               ];

This is automatically recognized as literals/numbers. If you do this, then you can just call it with:

- (IBAction)saveBtn:(id)sender 
{
  _teamNumber.text = [[NSString alloc] initWithFormat: @"%i", [_redOneTeams objectAtIndex:0]];
}

2- Another more convoluted way but to show you how you can unwrap numbers from NSStrings:

Keep your array declared with NSString elements and then get the value form the NSString as follows:

- (IBAction)saveBtn:(id)sender 
{
  _teamNumber.text = [[NSString alloc] initWithFormat: @"%i", [[_redOneTeams objectAtIndex:0] intValue]];
}

Hope this helps

Ah, I see. Xcode autocorrected to put @"%@" for my text. Thanks! I'll check on it tomorrow to see if it worked. — Louie Bertoncin, Mar 05 '13 at 04:03
It turns out my array was never even being initialized even though I had it in the custom initialization in the code that apple supplies when creating a new page... Weird. I ended up initializing the array in my button press method and it worked there. Thanks for the help though! — Louie Bertoncin, Mar 06 '13 at 01:40

score 0 · Accepted Answer · answered Mar 05 '13 at 04:05

There are two possibilities with your issue.

Just set a break point on initWithNibName and check if this method is triggering . I feel like this method is not getting called somehow. So you array is not getting set.
If you are able not find out why initWithNibName is not getting called then you can shift your code into viewDidLoad method.

Just try out these things probably you will catch issue.

How do I display an integer from an NSArray on a UILabel?

2 Answers2