how to prevent a class to be instantiated?

[Rommeo]

Hello,

 

My first question is;

if there is a class, and i dont want this class to be instantiated anywhere? How can i do this? What are the ways/keywords for this?

 

My second question is;

Are there type of classes that can't be instantiated? What are the names of these classes?

 

Thanks in advance.

 

[kicken]

The info you're looking for would be found by looking up the singleton class pattern. In this design a class is only constructed once by forcing the construction to be done by a static method of the class.

 

You can prevent external code from constructing instances of your class by making your __construct method private.