NSCalendarUnit – modifying unitFlags

Question

In my app I want to let user set display style of a date. I've considered to just modify unitFlags to achieve that. I mean this

NSUInteger unitFlags = NSYearCalendarUnit | NSMonthCalendarUnit | NSWeekCalendarUnit | NSDayCalendarUnit;

But here's the question: How can I add or remove a NSCalendarUnit to this integer?

I'm using NSCalendar to get NSDateComponents from a date.

Sorry if the question is too stupid, I wasn't working enough with bitwise operations :(

Answer 1

I am not sure if this is what you are looking for, but you can add a flag using the "bitwise or" operator:

unitFlags |= NSYearCalendarUnit;

and remove a flag using "bitwise and" in combination with "bitwise complement";

unitFlags &= ~NSYearCalendarUnit;

To check for a flag:

if ((unitFlags & NSYearCalendarUnit) != 0) {
    // NSYearCalendarUnit is set
} else {
    // NSYearCalendarUnit is not set
}