a multilevel hierarchy

   

/*
C#: The Complete Reference 
by Herbert Schildt 

Publisher: Osborne/McGraw-Hill (March 8, 2002)
ISBN: 0072134852
*/


/*  In a multilevel hierarchy, the  
    first override of a virtual method 
    that is found while moving up the 
    heirarchy is the one executed. */ 
  
using System;  
  
class Base {  
  // Create virtual method in the base class.   
  public virtual void who() {  
    Console.WriteLine("who() in Base");  
  }  
}  
  
class Derived1 : Base {  
  // Override who() in a derived class.  
  public override void who() {  
    Console.WriteLine("who() in Derived1");  
  }  
}  
  
class Derived2 : Derived1 {  
  // This class also does not override who().  
}  
 
class Derived3 : Derived2 {  
  // This class does not override who().  
}  
 
public class NoOverrideDemo2 {  
  public static void Main() {  
    Derived3 dOb = new Derived3();  
    Base baseRef; // a base-class reference  
  
    baseRef = dOb;   
    baseRef.who(); // calls Derived1's who()  
  }  
}