Re: Using NS[Int]Number for dictionary keys

[Richard Frith-Macdonald]

On 2005-08-30 19:38:13 +0100 Mark Dalrymple <bork@borkware.com> wrote:

> Greetings,
>
> I'm working with some folks that are wanting to put a large number of 
> objects into a dictionary, keyed by number.  When using string keys  
> created 
> with
>
>      string1 = [NSString stringWithFormat:@"%d", clauseNumber];
>      [clauseHashTable setObject:currentClause forKey:string1];
>
> with clauseNumber going from 1 to a bit over 1 million, It takes  about 6 
> seconds (2-way G5 running OS X) to populate a dictionary.
>
> When using NSNumbers,
>
>       number = [NSNumber numberWithInt: clauseNumber];
>       [clauseHashTable setObject: currentClause
>                        forKey: number];
>
> It takes about 21 minutes.  Using the same code with Apple's Cocoa  
> libraries 
> takes about 3 seconds.

Lousy hash implementation for NSNumber ... I have replaced it in CVS with a 
better one.