INTERFACE IN C# .NET

      

·      IT ACCESS BY REFERENCE

·      IN IT WE ARRANGE THE NAMING FUNCTION

·      WE NEVER CREATE THE BODY OF THE FUNCTION

·      IT IS USED TO CREATE THE ARCHITECTURE OF THE FUNCTION

·      THIS TECHNIQUE IS USED TO REPRESENT THE NAMING ARCHITECTURE

·      INTERFACE ARE IMPLEMNETED IN THE CLASS

·      IN INTERFACE WE CAN USE MULTIPLE AND HYBRID CONCEPT OF INHERITANCE

BOUNDARIES

·      IN INTERFACE METHOD IS OF ABSTRACT TYPE

·      INTERFACE IS BY DEFAULT PUBLIC KEYWORD SO NO NEED TO USED ACCESS MODIFIERS ON FUNTIONS

ON CLASS

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

namespace WindowsFormsApplication7

{

    public interface abc

    {

        int sum(int a, int b);

        int sub(int a, int b);

    }

    public interface abcd

    {

        void hello();

        int div(int a, int b);

      

    }

    class Class1:abc,abcd

    {

        public int sum(int a, int b)

        {

            return a + b;

        }

        public int sub(int a, int b)

        {

            return a - b;

        }

        public int div(int a, int b)

        {

            return a / b;

        }

        public void hello()

        {   System.Windows.Forms.MessageBox.Show("hello how are you");

        }

    }

}

ON BUTTON

   private void button1_Click(object sender, EventArgs e)

        {

            Class1 ob = new Class1();

            MessageBox.Show(ob.sum(12, 34).ToString());

            MessageBox.Show(ob.sub(23, 11).ToString());

            MessageBox.Show(ob.div(24, 6).ToString());

            ob.hello();

        }

ABSTRACT

·     Abstract class is a class that has no direct instances, but whose descendants may have direct instances

·      WE CANNOT CREATE THE OBJECT OF ABSTRACT CLASS

·      WE CAN DEFINE ABSTRACT AND NON ABSTRACT BOTH METHODS

·      IT IS AN ADVANCE IMPROVMENTS ON INTERFACE

·      USE OF ABSTRACT KEYWORD IS NECESSARY

·      BY DEFINITION IT IS ABSTRACT CLASS IF WE USED ABSTRACT KEYWORD IN ANY CLASS BUT NOT BY CODING

·    An abstract class cannot be a sealed class.

·    Use of virtual keyword is necessary on functions to override them in derived class

·    Use of abstract keyword is necessary to define abtract type functions means which has no body;

Abstract class aa

{

Public abstract int xyz();

}

Non abstract

  Public int abc()

{
}

If you HAVE MAKE THE BASE CLASS AN ABSTRACT CLASS THAN HAVE TO USED THE OVERRIDE KEYWORD IN THE DERIVED CLASS

Practical

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

namespace WindowsFormsApplication7

{

    abstract class Class2

    {

        public int sum(int a, int b)

        {

            return a + b;

        }

        public virtual int div(int a, int b)

        {

            return a / b;

        }

        public virtual int mul(int a, int b)

        {

            return a * b;

        }

        public abstract int aa(int a, int b);

    }

    class pawan : Class2

    {

        public override int aa(int a, int b)

        {

            return a % b;

        }

        public override int div(int a, int b)

        {

            return a / b;

        }

    }

}