NSNumber and float conversion?

[adamwaite]

I am trying to set an NSNumber as a float value that has been loaded using NSUserDefaults but i'm getting an error. I can't understand why...?

Here's my code:

[settingsData.sensitivitySettingValue floatValue] = [[NSUserDefaults standardUserDefaults] floatForKey:@"sensitivityKey"];

It works if I use a float on its own (i.e float myFloat = [[NSUserDefaults standardUserDefaults] floatForKey:@"sensitivityKey"]

, but I want the value available across all view controllers so I have defined it in a model class as an NSNumber.

So, please would anyone be able to advise me on why that statement wont work?

[BrianSlick]

Hint: [NSNumber numberWithFloat:blah];

[adamwaite]

I found a decent answer so going to post it up in case it may help someone else one day.....

Taking settingsData as an object of your datamodel class where sensitivitySettingValue is a variable declared as NSNumber using something as

[settingsData.sensitivitySettingValue floatValue]

actually fetches its value rather than setting a float value to it . You can either use the dot notation such as

settingsData.sensitivitySettingValue = [NSNumber numberWithFloat:[[NSUserDefaults standardUserDefaults] floatForKey:@"sensitivityKey"]];

That works.

[adamwaite]

Originally Posted by BrianSlick

Hint: [NSNumber numberWithFloat:blah];

Why wont this output 5 to the console? It is outputting 0?!

- (void)viewDidLoad
{
    [super viewDidLoad];
    
    float five = 5;
    
    settingsData.sensitivitySettingValue = [NSNumber numberWithFloat:five];
    
    float someFloat = [settingsData.sensitivitySettingValue floatValue];
    
    NSLog(@"%f", someFloat);

}

[BrianSlick]

My guess is that settingsData is nil.

[adamwaite]

Originally Posted by BrianSlick

My guess is that settingsData is nil.

Ah that sounds like it must be it. What do you mean when you say it is nil? How do I changed that? Do I have to alloc init it? Sorry, complete newbie with model classes.

[adamwaite]

ah yes, allocating it worked.

[adamwaite]

Thanks BrianSlick, got everything working now as it should. Learned a lot with your comments and feedback.