Singleton Pattern

[3raser]

(example I looked at: http://develturk.com/tags/selfinstance/)

 

I've looked into the singleton pattern and a few examples. I've understood most of its concept, but I still have a few things puzzling me. I noticed that you're not supposed to allow cloning (obviously) or the construction method as it shows in an example:

 

    //this object can not copy
    //except the getInstance() method.
    private function __clone() {}
   
    //prevent directly access
    //we want acces this only from getInstance method.
    private function __construct(){}

 

Do I also have to do this for child classes, or just the parent class?

[trq]

Child classes inherit all parent's properties and methods.