Question

I want calculate this operation with Xcode:

A*B*(DAYS)=R

DAYS= How many days are from past datepicker to today.

Today is the date setting of the iPhone. eg:

5*5*10

10= Days between yesterday and today.

THIS IS MY SITUATION:

my H
@interface ViewController : UIViewController

@property (strong, nonatomic) IBOutlet UITextField *a;
@property (strong, nonatomic) IBOutlet UITextField *b;
@property (strong, nonatomic) IBOutlet UILabel *r;

@property (strong, nonatomic) IBOutlet UIButton *result;

@property (strong, nonatomic) IBOutlet UIDatePicker *data;


@end

my M

- (IBAction)calculate:(id)sender {
    NSDate *past = _data.date ;
    NSDate *now =[NSString stringWithFormat:@"%@",nil];

    **float z = HOW MANY DAYS BETWEEN PICKER AND TODAY;** //this is a example

    float a = ([a.text floatValue]);
    float b = a*([b.text floatValue]);
    float r=  a*b*(z.text float);

    _result.text = [[NSString alloc]initWithFormat:@"%2.f",b];


}

I know that this is Wrong method….Can you help me?

Answer 1

You are computing number of days, so you can just use int instead of float.

NSDate *past = _data.date ;
NSDate *now = [NSDate date];

NSCalendar *gregorianCalendar = [[NSCalendar alloc]
                 initWithCalendarIdentifier:NSGregorianCalendar];
NSUInteger unitFlags = NSDayCalendarUnit;
NSDateComponents *components = [gregorianCalendar components:unitFlags
                                            fromDate:past
                                              toDate:now
                                             options:0];
z = [components day];

int a = a.text.intValue;
int b = a * b.text.intValue;
int r = a * b * z;
_result.text = [[NSString alloc] initWithFormat:@"%d", r];