Dec 16, 2009 · When inheriting an abstract class, a concrete child class must define the abstract methods, whereas an abstract class can extend another abstract class and abstract methods …

Oct 2, 2009 · When and why should abstract classes be used? I would like to see some practical examples of their uses. Also, what is the difference between abstract classes and interfaces?

Abstract Data Type (ADT) is a data type, where only behavior is defined but not implementation. Opposite of ADT is Concrete Data Type (CDT), where it contains an implementation of ADT. …

Why can't Java classes have abstract fields like they can with abstract methods? For example: I have two classes that extend the same abstract base class. These two classes each have a …

For abstract methods you have to explicibly state it, yes. For virtual methods it is more complicated. If you don't state the override keyword there, the original method will become …

In C#, when should you use interfaces and when should you use abstract classes? What can be the deciding factor?

In the following code, I create a base abstract class Base. I want all the classes that inherit from Base to provide the name property, so I made this property an @abstractmethod. Then I …

An abstract class cannot be instantiated by definition. In order to use this class, you must create a concrete subclass which implements all virtual functions of the class.

Nov 29, 2016 · By adding the feature of abstract methods and types you prevent the unintended use of an incomplete type by someone who doesn't realize that it's incomplete. It provides a …

Apr 25, 2017 · Abstract classes can be used to store methods in an OOP-based "library"; since the class doesn't need to be instantiated, and would make little sense for it to be, keeping …