Nullable<T>.HasValue Property
.NET Framework 4.5
Gets a value indicating whether the current Nullable<T> object has a value.
Namespace: System
Assembly: mscorlib (in mscorlib.dll)
Property Value
Type: System.Booleantrue if the current Nullable<T> object has a value; false if the current Nullable<T> object has no value.
If the HasValue property is true, the value of the current Nullable<T> object can be accessed with the Value property.
The following code example returns the value of a Nullable<T> object if that object has a defined value; otherwise, a default value is returned.
// 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. */
Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
