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iosnsdatenscalendarnsdatecomponentsweek-number

Crash in NSDateComponents weekOfYear

I'm trying to get the number of the week of the year out of an NSDate with this code:

int which = NSYearCalendarUnit | NSMonthCalendarUnit | NSHourCalendarUnit | NSMinuteCalendarUnit | NSSecondCalendarUnit | NSWeekOfYearCalendarUnit | NSQuarterCalendarUnit;
NSDate* date= [NSDate date];
NSDateComponents* comps= [[NSCalendar currentCalendar] components:which fromDate:date];

today.weekNumber= comps.weekOfYear;

However, for some reason it is crashing and stating:

reason: -[NSDateComponents weekOfYear]: unrecognized selector sent to instance

The other components work just fine when I uncomment the weeknumber part:

int which = NSYearCalendarUnit | NSMonthCalendarUnit | NSHourCalendarUnit | NSMinuteCalendarUnit | NSSecondCalendarUnit | NSWeekOfYearCalendarUnit | NSQuarterCalendarUnit;
NSDate* date= [NSDate date];
NSDateComponents* comps= [[NSCalendar currentCalendar] components:which fromDate:date];

//   today.weekNumber= comps.weekOfYear;
today.month= comps.month;
today.year= comps.year;
today.quarter= comps.quarter;
today.hour= comps.hour;
today.minute= comps.minute;
today.second= comps.second;

According to the docs, NSDateComponents should have a property called weekOfYear, shouldn't it?

I'm confused, really.

Solution

  • -weekOfYear method is available in NSDateComponents starting iOS 5.0 and so if you're trying to use that method on earlier OS versions that will result in the crash.