Abstract Class

Abstract Class:

• When a class is not providing full functionality it recommended to declare that class as an Abstract class.
• Method with out body is called an abstract method.
• Ex: public abstract void GetArea ();
• When class contain at least one abstract method then that class must be declared as abstract class.
• All the abstract method must be overridden in the derived class.
• We cant create object for Abstract class.

Ex :

using System;

using System.Collections.Generic;

using System.Linq;

using System.Web;

using System.Web.UI;

using System.Web.UI.WebControls;

public partial class AbstractClassSammple : System.Web.UI.Page

{

protected void Page_Load(object sender, EventArgs e)

{

Circle c = new Circle ();

c.print();

Response.Write(c.findarea()+" ");

Response.Write("
"+c.print());

}

}

public abstract class Shape

{

private int x = 10;

private int y = 20;

public int print()

{

return (x + y);

}

public abstract double findarea();

}

public class Circle : Shape

{

private int r = 10;

public override double findarea()

{

double a = 3.14 * r * r;

return (a);

}

}