Can't do mathematical operations with int from NSUserDefaults

Question

i have integer data, stored in NSUserDefaults, there is my code:

- (IBAction)addButton:(id)sender {
      NSInteger oldValue = [[NSUserDefaults standardUserDefaults] integerForKey:@"myValue"];

    NSString *string1=[addTextField text];
    int add = [string1 floatValue];  
    int new = globalCalories;
    int old=oldValue;

    if(recomended.text==[NSString stringWithFormat:@"%i", oldValue]){
        **self.day = (int)roundf(old-add);
        dayLeft.text=[NSString stringWithFormat:@"%d", oldValue-add];
    }**

    else
    {
        self.day=(int)roundf(new-add);
        dayLeft.text=[NSString stringWithFormat:@"%d", day];
    }
}

I copied all of button action code, just in case, but i did mark with bold strings of code, that appear to not work. So, it suppose to do mathematical operations with stored data (oldValue), but when i launch programs, it dosnt, in fact, it does, but instead of valid value program "think" that oldValue is 0 (instead of valid value).

So, when it contain, for example, number 2000, and I launch program and enter in text field 500, it suppose to be 1500 (2000-500), but it shows -500.

Check this question: http://stackoverflow.com/questions/4855771/cannot-set-nsuserdefaults-field — Isaac, Feb 26 '12 at 13:36

score 1 · Answer 1 · edited Jul 11 '18 at 12:10

1

You can convert recommended.text to integer by using this:

int recommendedValue = [recommended.text intValue];

then compare the numbers.

edited Jul 11 '18 at 12:10

MattAllegro

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answered Feb 26 '12 at 22:29

Diana

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score 0 · Answer 2 · answered Feb 26 '12 at 13:34

0

The problem is that == compared the address es of the NSString and not their values (see many SO questions). To compare strings use the isEqualToString: method.

However in this case it would be even better to compare the numbers ie convert recomended.text to the number and use a intValue method on dayLeft.

answered Feb 26 '12 at 13:34

mmmmmm

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i wonder how to convert label.text to that number? Please tell me – Necrosoft Feb 26 '12 at 13:42
How is recomended.text set and what type is it? – mmmmmm Feb 26 '12 at 13:44
recomended.text= [NSString stringWithFormat:@"%i", globalCalories]; – Necrosoft Feb 26 '12 at 13:46
why not store globalCalories in an int in recommended – mmmmmm Feb 26 '12 at 13:50
What matters is the variable's type not its scope – mmmmmm Feb 26 '12 at 14:44

Can't do mathematical operations with int from NSUserDefaults

2 Answers2