' This code example demonstrates the Nullable(Of T).HasValue 
' and Value properties.

Imports System

Class Sample
    Public Shared Sub Main() 
        Dim myNow As Nullable(Of DateTime)

    '  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 = Nothing
        Display(myNow, "2) ")
    End Sub 'Main
    
    ' Display the date and time.
    Public Shared Sub Display(ByVal displayDateTime As Nullable(Of DateTime), _
                              ByVal title As String) 

    ' If the HasValue property for the nullable of DateTime input argument is true, 
    ' display the value of the input argument; otherwise, display that no value is
    ' defined for the input value.
        Console.Write(title)
        If displayDateTime.HasValue = True Then
            Console.WriteLine("The date and time is {0:F}.", displayDateTime.Value)
        Else
            Console.WriteLine("The date and time is not defined.")
        End If
    End Sub 'Display 

End Class 'Sample '

'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.
'

// 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.

*/