What is abstract class with example program in a c# code

Question

Vulpes · Answer

Here's a very simple example of an abstract class in C#. Notice that abstract methods are virtual and therefore exhibit polymorphic behaviour. However unlike a normal 'virtual' method an abstract method cannot have a body. using System; class Test { static void Main() { Parent p = new Child(); p.SomeMethod(); // calls Child's version Console.ReadKey(); } } abstract class Parent { public abstract void SomeMethod(); // no body } class Child : Parent { public override void SomeMethod() { Console.WriteLine(SomeMethod has been called); } }

Satyapriya Nayak · Answer

Hi Fire Abstract class: - It is an incomplete class whose object cannot be created. It contains the skeleton of the method which is implemented by derived class. The abstract class is prefixed by the keyword MustInherit. The methods with in the class are prefixed by MustOverride keyword. The derived class procedure which implements the abstract class is prefixed by Overrides keyword. Program Public Class Form1 Private Sub Button1_Click( ByVal sender As System.Object ByVal e As System.EventArgs) Handles Button1.Click Dim a As New raj1 a.ravi( Rahul ) End Sub Public MustInherit Class raj Public MustOverride Sub ravi( ByVal s As String ) End Class Public Class raj1 Inherits raj Public Overrides Sub ravi( ByVal s As String ) MsgBox( Hello: & s) End Sub End Class End Class Interface : - It is a specification of class members not the implementation of members. It is the substitute of multiple inheritance more than one interface can be implemented by a single class. The members with in the interface are not defined. It is public by default. Variables cannot be declared within the interface. Both sub procedure and function procedure can be stored in the interface. Program Public Class Form2 Private Sub Button1_Click( ByVal sender As System.Object ByVal e As System.EventArgs) Handles Button1.Click Dim a As New raj1 a.sagar(25) a.amit( Abhijeet ) MsgBox(a.rahul(10 20)) End Sub Public Interface raj Sub sagar( ByVal x As Integer ) Sub amit( ByVal s As String ) Function rahul( ByVal x As Integer  ByVal y As Integer ) End Interface Public Class raj1 Implements raj Public Sub amit( ByVal s As String ) Implements raj.amit MsgBox( Hello: & s) End Sub Public Function rahul( ByVal x As Integer  ByVal y As Integer ) As Object Implements raj.rahul Dim z As Integer z = x + y Return z End Function Public Sub sagar( ByVal x As Integer ) Implements raj.sagar MsgBox(x) End Sub End Class End Class For Csharp code Please refer the below links http://www.codeproject.com/Articles/6118/All-about-abstract-classes http://www.c-sharpcorner.com/uploadfile/annathurai/abstract-class-in-C-Sharp/ Thanks