Nullable<T>.Value Property

// This code example demonstrates the Nullable<T>.HasValue  
// and Value properties. 

using System;

class Sample 
{
    public static void Main() 
    {
    DateTime? myNow;

//  Assign the current date and time to myNow then display its value.
    myNow = DateTime.Now;
    Display(myNow, "1) ");

//  Assign null (Nothing in Visual Basic) to myNow then display its value.
    myNow = null;
    Display(myNow, "2) ");
    }

// Display the date and time. 
    public static void Display(DateTime? displayDateTime, string title)
    {
// If a value is defined for the displayDatetime argument, display its value; otherwise,  
// display that no value is defined.
    Console.Write(title);
    if (displayDateTime.HasValue == true)
        Console.WriteLine("The date and time is {0:F}.", displayDateTime.Value);
    else
        Console.WriteLine("The date and time is not defined.");
    }
}

/*
This code example produces the following results:

1) The date and time is Tuesday, April 19, 2005 4:16:06 PM.
2) The date and time is not defined.

*/