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

FROM : Ken Thomases
DATE : Fri Jun 06 21:05:27 2008

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