Guid.Empty Field (System)

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.NET Framework Class Library
Guid.Empty Field

Updated: August 2011

A read-only instance of the Guid structure whose value is all zeros.

Namespace:  System
Assembly:  mscorlib (in mscorlib.dll)
Syntax

Visual Basic
Public Shared ReadOnly Empty As Guid
C#
public static readonly Guid Empty
Visual C++
public:
static initonly Guid Empty
F#
static val Empty: Guid
Remarks

You can compare a GUID with the value of the Guid.Empty field to determine whether a GUID is non-zero. The following example uses the Equality operator to compare two GUID values with Guid.Empty to determine whether they consist exclusively of zeros.

Visual Basic

Module Example
   Public Sub Main()
      ' Create a GUID and determine whether it consists of all zeros.
      Dim guid1 As Guid = Guid.NewGuid
      Console.WriteLine(guid1)
      Console.WriteLine("Empty: {0}", guid1 = Guid.Empty)
      Console.WriteLine()

      ' Create a GUID with all zeros and compare it to Empty.
      Dim bytes(15) As Byte
      Dim guid2 As New Guid(bytes)
      Console.WriteLine(guid2)
      Console.WriteLine("Empty: {0}", guid2 = Guid.Empty)
   End Sub
End Module
' The example displays output like the following:
'       11c43ee8-b9d3-4e51-b73f-bd9dda66e29c
'       Empty: False
'       
'       00000000-0000-0000-0000-000000000000
'       Empty: True


C#

using System;

public class Example
{
   public static void Main()
   {
      // Create a GUID and determine whether it consists of all zeros.
      Guid guid1 = Guid.NewGuid();
      Console.WriteLine(guid1);
      Console.WriteLine("Empty: {0}\n", guid1 == Guid.Empty);

      // Create a GUID with all zeros and compare it to Empty.
      Byte[] bytes = new Byte[16];
      Guid guid2 = new Guid(bytes);
      Console.WriteLine(guid2);
      Console.WriteLine("Empty: {0}", guid2 == Guid.Empty);
   }
}
// The example displays output like the following:
//       11c43ee8-b9d3-4e51-b73f-bd9dda66e29c
//       Empty: False
//       
//       00000000-0000-0000-0000-000000000000
//       Empty: True


Version Information

.NET Framework

Supported in: 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Portable Class Library

Supported in: Portable Class Library
Platforms

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
See Also

Reference

Change History

Date

History

Reason

August 2011

Added the Remarks section.

Customer feedback.