Calculate person’s age from NSDate #objective-c #datetime #basic

nsdate_to_age.m

NSDate *birthday = value;
        
NSDate *now = [NSDate date];
NSDateComponents *ageComponents = [[NSCalendar currentCalendar]
                                           components:NSYearCalendarUnit
                                           fromDate:birthday
                                           toDate:now
                                           options:0];
NSInteger age = [ageComponents year];