Encapsulation and Inheritance

Encapsulation: 

Encapsulation is a process of binding the data members and member functions into a single unit.

Example 

A class can contain data fields and methods.

Consider the following class

public class Aperture

{

protected double height;

protected double width;

protected double thickness;

public double get volume()

{

Double volume=height * width * thickness;

if (volume<0)

return 0;

return volume;

}

}
 
In this example we encapsulate some data such as height, width, thickness and method Get Volume. Other methods or objects can interact with this object through methods that have public access modifier.

Inheritance:

Inheritance is a process of deriving the new class from already existing class.

C# is a complete object oriented programming language. Inheritance is one of the primary concepts of object-oriented programming. It allows you to reuse existing code. Through effective use of inheritance, you can save lot of time in your programming and also reduce errors, which in turn will increase the quality of work and productivity. 

There are 5 types of inheritances in C#. they are

1.Single Inheritance
2.Multilevel INheritance
3.Multiple Inheritance
4.Hybrid Inheritance
5.Hierarchical inheritance.


Single Inheritance :

when a single derived class is created from a single base class then the inheritance is called as single inheritance.

   
Program :
 
using System;
namespace ProgramCall

{
   class BaseClass

    {
      //Method to find sum of give  2 numbers

        public int FindSum(int x, int y)

        {

          return (x + y);

        }

        //method to print given 2 numbers

        //When declared protected , can be accessed only from inside the derived class

        //cannot access  with the instance of  derived class

        protected void Print(int x, int y)

        {

            Console.WriteLine("First Number: " + x);

            Console.WriteLine("Second Number: " + y);

         }

    }


    class Derivedclass : BaseClass

    {

      public void Print3numbers(int x, int y, int z)

        {

            Print(x, y); //We can directly call baseclass members

            Console.WriteLine("Third Number: " + z);

        }


    }

     class MainClass

    {

      static void Main(string[] args)

        {

            //Create instance for derived class, so that base class members
            // can also  be accessed

            //This is possible because  derivedclass is inheriting base class

             Derivedclass instance = new Derivedclass();

            instance.Print3numbers(30, 40, 50); //Derived class internally calls base class method.

            int sum = instance.FindSum(30, 40); //calling base class method with derived class instance

            Console.WriteLine("Sum : " + sum);

            Console.Read();

        }

    }

}

Output

First Number: 30
Second Number: 40
Third Number: 50
Sum : 70