Class C# Tutorial

using System;
public class BaseClass
{
  public string lastName;
  public string firstName;
  public BaseClass(string lastName, string firstName)
  {
    Console.WriteLine("In BaseClass constructor");
    this.lastName = lastName;
    this.firstName = firstName;
    Console.WriteLine("this.lastName = " + this.lastName);
    Console.WriteLine("this.firstName = " + this.firstName);
  }
  public void DisplayfirstName()
  {
    Console.WriteLine("In BaseClass DisplayfirstName() method");
    Console.WriteLine("firstName = " + firstName);
  }
}
public class DerivedClass : BaseClass
{
  public new string firstName;
  public DerivedClass(string lastName, string firstName) : base(lastName, "Test")
  {
    Console.WriteLine("In DerivedClass constructor");
    this.firstName = firstName;
    Console.WriteLine("this.firstName = " + this.firstName);
  }
  public new void DisplayfirstName()
  {
    Console.WriteLine("In DerivedClass DisplayfirstName() method");
    Console.WriteLine("firstName = " + firstName);
    base.DisplayfirstName();
  }
}
class MainClass
{
  public static void Main()
  {
    Console.WriteLine("Creating a DerivedClass object");
    DerivedClass myDerivedClass = new DerivedClass("A", "B");
    Console.WriteLine("Back in Main() method");
    Console.WriteLine("myDerivedClass.lastName = " + myDerivedClass.lastName);
    Console.WriteLine("myDerivedClass.firstName = " + myDerivedClass.firstName);
    Console.WriteLine("Calling myDerivedClass.DisplayfirstName()");
    myDerivedClass.DisplayfirstName();
  }
}
Creating a DerivedClass object
In BaseClass constructor
this.lastName = A
this.firstName = Test
In DerivedClass constructor
this.firstName = B
Back in Main() method
myDerivedClass.lastName = A
myDerivedClass.firstName = B
Calling myDerivedClass.DisplayfirstName()
In DerivedClass DisplayfirstName() method
firstName = B
In BaseClass DisplayfirstName() method
firstName = Test