Derived Class

Techopedia explains Derived Class

Following are some of the features of derived classes in C#:

• As in Java and unlike C++, a derived class cannot have more than one base class but can be derived from more than one interface. However, it inherits all the members of its parent base classes declared in its inheritance hierarchy, due to transitive nature of inheritance
• Access modifiers used in the declaration statement of derived class specify the permissions to use members of its base class
• Code in the constructor of a derived class which is executed during its creation, will be executed only after executing constructor of its base class
• Derived class has to use the modifier, ‘override’ to declare the virtual method (declared in its base class with ‘virtual’ keyword) that has to be overridden. Only instance methods and properties can be overridden
• Derived class can have new method that hides the virtual method declared in base (with similar signature) by using the keyword, ‘new’. To access the method in base class from derived class, ‘base’ keyword can be used
• A class can prevent derivation by declaring it as ‘sealed’ and cannot be used as base class
• A derived class with base class as an abstract class can be instantiated if the derived class is not declared abstract and derived class has the implementation for all abstract methods declared in the base class