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Guid.CompareTo Method (Object)

Compares this instance to a specified object and returns an indication of their relative values.

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

public int CompareTo(
	Object value


Type: System.Object

An object to compare, or null.

Return Value

Type: System.Int32
A signed number indicating the relative values of this instance and value.

Return value


A negative integer

This instance is less than value.


This instance is equal to value.

A positive integer

This instance is greater than value, or value is null.




value is not a Guid.

Any instance of Guid, regardless of its value, is considered greater than null.

The value parameter must be null or an instance of Guid; otherwise, an exception is thrown.

The following example demonstrates how to attach and read a Guid object as an attribute on a user-defined class or interface.

using System;
using System.Runtime.InteropServices;

// Guid for the interface IMyInterface.
interface IMyInterface
    void MyMethod();

// Guid for the coclass MyTestClass.
public class MyTestClass : IMyInterface
    public void MyMethod() {}

    public static void Main( string []args )
        GuidAttribute IMyInterfaceAttribute = (GuidAttribute) Attribute.GetCustomAttribute(typeof(IMyInterface), typeof(GuidAttribute));

        System.Console.WriteLine("IMyInterface Attribute: " + IMyInterfaceAttribute.Value );    

        // Use the string to create a guid.
        Guid myGuid1 = new Guid(IMyInterfaceAttribute.Value );
        // Use a byte array to create a guid.
        Guid myGuid2 = new Guid(myGuid1.ToByteArray());

        if (myGuid1.Equals(myGuid2))
            System.Console.WriteLine("myGuid1 equals myGuid2");
            System.Console.WriteLine("myGuid1 does not equal myGuid2" );

        // Equality operator can also be used to determine if two guids have same value. 
        if ( myGuid1 == myGuid2 )
            System.Console.WriteLine( "myGuid1 == myGuid2" );
            System.Console.WriteLine( "myGuid1 != myGuid2" );
// The example displays the following output: 
//       IMyInterface Attribute: F9168C5E-CEB2-4faa-B6BF-329BF39FA1E4 
//       myGuid1 equals myGuid2 
//       myGuid1 == myGuid2

.NET Framework

Supported in: 4.5.2, 4.5.1, 4.5, 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

.NET for Windows Phone apps

Supported in: Windows Phone 8.1, Windows Phone 8, Silverlight 8.1

Windows Phone 8.1, Windows Phone 8, Windows 8.1, Windows Server 2012 R2, 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.

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