June 10, 2002 - Understanding Abstract Classes

Yehuda Shiran June 10, 2002
Understanding Abstract Classes
Tips: June 2002

Yehuda Shiran, Ph.D.
Doc JavaScript

You need to mark class members that have no implementation with the abstract modifier. You also need to label a class containing such members as abstract. A class with abstract members cannot be instantiated with the new operator. You can derive both abstract and non-abstract classes from an abstract base class. Interfaces are implicitly abstract. They cannot be instantiated, and must be implemented by a non-abstract class. Therefore, you cannot mark interfaces and their members as abstract. You may not combine the abstract modifier with the other inheritance modifier, final. You may not combine either of these inheritance modifiers (abstract and final) with the static modifier.

To learn more about JScript .NET, go to Column 110, JScript .NET, Part IV: Inheritance.