In this article, I will explain you Inheritance
in Visual Basic .NET
Inheritance
Reusability is an important feature
of Object-Oriented Programming. If we can reuse something that already exists
it's always time saving and useful rather than creating the same thing again. By
reusing the class that already tested and debugged can save the time and effort
of testing and developing it again. Inheritance is the
process of deriving a new class from an existing class. The existing class is
called Base class and the new class is called Derived class. When a Derived
class is created through implementation inheritance, It automatically gains all
the members and implementation of the Base class. The behavior of the Base class
can be changed by writing code in the Derived class. This technique is called
overriding. With the new implementations of Derived class inherited methods can
also be override. Inheritance allows you to build a hierarchy of related classes
and to reuse functionality defined in existing classes. All classes created with
Visual Basic are inheritable by default. In Visual Basic we use the
Inherits keyword to inherit one class from
other. This code show you how to declare the inherit class:
Public Class Base
----
----
End Class
Public Class Derived
Inherits
Base
'Derived class inherits the Base class
----
----
End Class
Derived
classes inherit, and can extend the methods, properties, events of the Base
class. With the use of inheritance we can
use the variables, methods, properties, events etc, from the Base class and add
more functionality to it in the Derived class. The following code show you how
inheritance works:
Imports System.Console
Module Module1
Sub Main()
Dim Obj As New Derived()
WriteLine(Obj.sum())
Read()
End Sub
End Module
Public Class Base
'base class
Public A As Integer = 20
Public B As Integer = 40
Public Function
add() As Integer
Return A + B
End Function
End Class
Public Class Derived
Inherits
Base
'derived class.Class Derived inherited from
class Base
Public C As Integer = 50
Public Function
sum() As Integer
'using the variables, function from
base class and adding more functionality
Return A + B + C
End Function
End Class
The output of this code is:
Summary
Hope this article help you to understand
Inheritance in Visual Basic .NET