[Newbies] class variable vs class instance variable uses

Miguel Enrique Cobá Martinez miguel.coba at gmail.com
Tue Aug 4 18:31:41 UTC 2009


El mar, 04-08-2009 a las 18:46 +0200, Bert Freudenberg escribió:
> On 04.08.2009, at 17:28, Miguel Enrique Cobá Martinez wrote:
> 
> > What is the difference between a class variable like Current in  
> > Locale class:
> 
> 
> A class variable exists once per image. A class instance variable  
> exists once per subclass.
> 
> If your singleton class has no subclasses, it doesn't matter. If it  
> has subclasses, then each subclass will have a different singleton if  
> you use a class instance variable. With a class variable, you only  
> have one singleton for all subclasses.
> 

Woa, thanks Bert and Hernán, that was a really clear explanation. Now I
understand the issues here.

Cheers,
Miguel Cobá

> - Bert -
> 
> 
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