Re: Using NSSortDescriptor to reverse sort an NSArray containing NSString objects

FROM : Andrew Merenbach
DATE : Fri Jun 06 21:26:52 2008

Quoting Ken Thomases <<email_removed>>:

> On Jun 6, 2008, at 3:43 AM, George Stuart wrote:
>

>> NSSortDescriptor *desc = [[NSSortDescriptor alloc] initWithKey:nil 
>> ascending:NO selector:@selector(localizedCompare:)];
>> NSArray *sortedArray = [unsortedArray 
>> sortedArrayUsingDescriptors:[NSArray arrayWithObject:desc]];
>> [desc release];
>>
>> That seems to work just fine... but I'm worried.  I "guessed" at 
>> using the key of "nil" since I want the actual objects in the array 
>>  to be the target for the @selector.  Is it a fluke that this 
>> works?  I don't want to rely on undefined behavior.

>
> Hmm.  Good question.  You could use @"description" as the key to
> eliminate the uncertainty.  Or maybe @"self".
>
> Cheers,
> Ken
>


Hi,

This may not be an option in every case, but would making a "wrapper" 
class for your strings work?  It'd just be a basic class with an 
accessor/property and a corresponding ivar that would then be the sort 
key.

Cheers,
Andrew