Source Code -Abstract Classes with Example

Example for Abstract Classes:

using System;

namespace abstractSample

{

      //Creating an Abstract Class

      abstract class absClass

      {

            //A Non abstract method

            public int AddTwoNumbers(int Num1, int Num2)

            {

                return Num1 + Num2;

            }

            //An abstract method, to be

            //overridden in derived class

            public abstract int MultiplyTwoNumbers(int Num1, int Num2);

      }

      //A Child Class of absClass

      class absDerived:absClass

      {

            [STAThread]

            static void Main(string[] args)

            {

               //You can create an

               //instance of the derived class

               absDerived calculate = new absDerived();

               int added = calculate.AddTwoNumbers(10,20);

               int multiplied = calculate.MultiplyTwoNumbers(10,20);

               Console.WriteLine("Added : {0}, 

                       Multiplied : {1}", added, multiplied);

            }

            //using override keyword,

            //implementing the abstract method

            //MultiplyTwoNumbers

            public override int MultiplyTwoNumbers(int Num1, int Num2)

            {

                return Num1 * Num2;

            }

      }

}