using System;

public class Program : gradchildClass

{

​

    public Program(){

        Console.WriteLine("ctor of program");

    }

    public void testProgram(){

        Console.WriteLine("method of program");

    }

    public void methodOverloading(){

        Console.WriteLine("child Class --> using same method in both class to test which method gets called for which class object");

    }

    public virtual void checkVirtualBehaviour(){

        Console.WriteLine("Program ---> what happen if I don not write override method");

    }

    public static void Main()

    {

        Console.WriteLine("instance of program created");

        Program p = new Program();

        //p has access to all 4 methods of 4 classes

        p.methodOverloading();

        p.checkVirtualBehaviour();

        Console.WriteLine("============================");

        Console.WriteLine("instance of gradchildClass created");

        gradchildClass g = new Program(); 

        //g has access to 3  methods but not to testProgram() method

        g.methodOverloading();

        g.checkVirtualBehaviour();

        Console.WriteLine("============================");

    }

}

​

public class parentClass

{

    public void testparentClass(){

        Console.WriteLine("method of parentClass");

    }

    public parentClass(){

        Console.WriteLine("Parent Class ctor");

    }

} 

​

public class childClass : parentClass

{

​

    public void testchildClass(){

        Console.WriteLine("method of childClass");

    }

    public childClass(){

        Console.WriteLine("child Class ctor");

    }

}

​

public class gradchildClass : childClass

{

​

    public void testgradchildClass(){

        Console.WriteLine("method of gradchildClass");

    }

​

    public void methodOverloading(){

        Console.WriteLine("Parent Class --> using same method in both class to test which method gets called for which class object");

    }

    public virtual void checkVirtualBehaviour(){

        Console.WriteLine("what happen if I don not write override method");

    }

    public gradchildClass(){

        Console.WriteLine("gradchildClass Class ctor");

    }

}