Re: NSNumber numberWithBool

[Richard Frith-Macdonald]

On 8 Jun 2007, at 20:08, Sebastian Reitenbach wrote:

> Hi,
>
> while trying to get opengroupware running with gnustep-base I  
> stumbled about
> the different return values of +NSNumber numberWithBool.
> Running the following test tool:
> #include <Foundation/Foundation.h>
>
> int main (int argc, char **argv) {
>         NSLog(@"numberWithInt: %@, numberWithBool: %@", [NSNumber
> numberWithInt:YES], [NSNumber numberWithBool:YES]);
>         NSLog(@"numberWithInt: %@, numberWithBool: %@", [NSNumber
> numberWithInt:NO], [NSNumber numberWithBool:NO]);
>         return 0;
> }

That's not different return values of numberWithBool: and numberWithInt:

What the '%@' format string does is print the results of applying the  
-description method to the object, so you are logging the way the - 
description of the objects differs.

Now, the documentation for the -description method (Apple's  
documentation for the NSObject protocol) says:

'Returns an NSString object that describes the contents of the  
receiver. The debugger’s print-object command indirectly invokes this  
method to produce a textual description of an object.'

I read that as meaning that the string produced is for debug  
purposes, and feel that it implies that code should not depend on a  
particular format of the string content.  So it really should not  
matter exactly what is printed out ... both libFoundation and gnustep- 
base are correct, and code which depends upon either behavior is  
therefore incorrect.