Question

I’ve got a NSArray with a bunch of EKCalendar Objects in it. I need to sort them alphabetically. I’m new to selectors but I think I need something like…

NSArray *array = [otherArray sortedArrayUsingSelector:@selector('localizedCaseInsensitiveCompare:title')];

Cheers

Answer 1

You cannot do it that way. Instead do the following:

NSArray *sortedArray = [array sortedArrayUsingComparator: ^(id obj1, id obj2) {
    EKCalendar *cal1 = (EKCalendar *)obj1;
    EKCalendar *cal2 = (EKCalendar *)obj2;
    return [cal1.title localizedCaseInsensitiveCompare:cal2.title];
}];

Edit – an explanation:

-sortedArrayUsingComparator takes what is called a ‘block’ (an inline function) that must return an NSComparisonResult. All the hard work is done for you, as your block is run for as many pairs of objects as is needed to establish the correct order. Then all this does is cast each object type to an EKCalendar and then compare the two titles. You can adapt this to work for any type of object.