C#.NET ---- SINGLE INHERITANCE

Single inheritance :

The process of creating one new class by derived from a single class is known as single Inheritance.

A simple example for single inheritance is father and son . a father property is can a chance to us        by son like their relationship, inheritance forms a relationship called "IS A' for suppose
 "Man is a Human ".

       base class = Human

       derived class = Man
After inheritance , A Derived class can access Base class properties , But The Base cannot have a permission to access Derived class properties 

Define a base class :

class  <BaseClassName >

{

 //data members of super class

 //methods of super class

 }

EX :
      class A
     {
        String str = "base class" ;
        public void Print()
        {
            Console.WriteLine("this is "+ str);
         }
      }

Here we write a normal class A with str as member variable and Print() member method 

Define a derived class:

Class < SubClassName> : < SuperClassName >

{

 //data members of sub class

 //methods of sub class

 }
   Ex : 
       class B : A
      {
        string str2 = "child class";
        public void print2()
       {
           print();                  // accessing Class A method with out using object
           Console.WriteLine(str2+" is derived from " + str);
        }
      }

Here By using colon ' : ' operator we can do inheritance from A to B , in Class B we can directly access Class A properties like print() method because they are inherited.


Accessing base class through derived class:

<subclassname> objectname = new  <subclassname>();

     objectname.SuperClassMethod();
                                or
     variable = objectname.SuperClassVarible ;

 Ex :
  
Class Program
{
   B b = new B(); // creating a sub class object
    b.print(); // accessing Class A method through object
    b.print2() ;

   Console.ReadKey();
}

Here we create a sub class object b and using sub class object only we can access directly the base class methods.
output  :
              this is base class
              this is base class
              child class is derived from base class

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Program 2 : 

Write a program on single inheritance like entering details in Base class and print that details in Derived class ?

/** A program on single inhertance **/
using System;
namespace InheritanceDemo
{
    class ClsParent    // creating parent class or base class
    {
        public  string source, destination; // base class variables 
        public void Reservation() // base class method
        {
            Console.Write("Enter city name where your are in now : ");
            source = Console.ReadLine();
            Console.Write("Enter city name where you need to go : ");
            destination = Console.ReadLine();
        }
    }
    class ClsChid : ClsParent  // creating child class using : colon operator
    {
         double amount;
        public void calAmount() // derived class method
        {
           
            amount=1000;
        }
        public void DisplayReservationDetails() // derived class method
        {
            Console.Write("\nfyour are  travling from "+source); // source is accessible because it is inherited from parent class
            Console.WriteLine(" to "+destination);  // destination is accessible because it is inherited from parent class
            Console.WriteLine("fare is :"+amount);   // amount is child class variable only             
        }
   
    }
    class Program
    {
        static void Main(string[] args)
        {
            ClsChid obj = new ClsChid(); // creating object for derived class
            obj.Reservation();   // using derived class object accessing base class method 
            obj.calAmount();        // as usual accesing member methods 
            obj.DisplayReservationDetails(); // as usual accessig member methods
            Console.ReadKey();
        }
    }
}

Output :

Enter city name where you are in now : hyderabad 

Enter city name where yor need to go : vijayawada

your are  travling from hyderabad to vijayawada

face is : 1000

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