[Newbies] class variable vs class instance variable uses
Bert Freudenberg
bert at freudenbergs.de
Tue Aug 4 16:46:14 UTC 2009
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.
- Bert -
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