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

FROM : Adam R. Maxwell
DATE : Fri Jun 06 23:16:23 2008

On Friday, June 06, 2008, at 02:07PM, "George Stuart" <george.<email_removed>> wrote:

>The suggestion of using a keyPath of @"self" presents another question:
>1)  I assume NSSortDescriptor is using valueForKeyPath:, which in 
>turns calls valueForKey: some number of times, to get the object for 
>the keyPath I specified.  Is it defined behavior that sending an 
>object valueForKey:@"self" will return the object itself? 


I always use self as the key path in cases like this, since -[NSObject self] is documented to return the receiver.  It has the advantage of working with objects other than strings.

> I guess 
>this is ultimately the same as my original question, "is it defined 
>behavior that sending an object valueForKey:nil will return the object 
>itself?"


Not as far as I know; I'd expect it to return nil or die with an assertion failure.

--
Adam