Compares two objects for equivalence, where string comparisons are case-sensitive.
Namespace:
System.Collections
Assembly:
mscorlib (in mscorlib.dll)
Visual Basic (Declaration)
<SerializableAttribute> _
<ComVisibleAttribute(True)> _
Public NotInheritable Class Comparer _
Implements IComparer, ISerializable
[SerializableAttribute]
[ComVisibleAttribute(true)]
public sealed class Comparer : IComparer,
ISerializable
[SerializableAttribute]
[ComVisibleAttribute(true)]
public ref class Comparer sealed : IComparer,
ISerializable
public final class Comparer implements IComparer, ISerializable
This class is the default implementation of the IComparer interface. The CaseInsensitiveComparer class is the implementation of the IComparer interface that performs case-insensitive string comparisons.
Comparison procedures use the Thread..::.CurrentCulture of the current thread unless otherwise specified. String comparisons might have different results depending on the culture. For more information on culture-specific comparisons, see the System.Globalization namespace and Encoding and Localization.
The following code example shows how Compare returns different values depending on the culture associated with the Comparer.
Imports System
Imports System.Collections
Imports System.Globalization
Public Class SamplesComparer
Public Shared Sub Main()
' Creates the strings to compare.
Dim str1 As [String] = "llegar"
Dim str2 As [String] = "lugar"
Console.WriteLine("Comparing ""{0}"" and ""{1}"" ...", str1, str2)
' Uses the DefaultInvariant Comparer.
Console.WriteLine(" Invariant Comparer: {0}", Comparer.DefaultInvariant.Compare(str1, str2))
' Uses the Comparer based on the culture "es-ES" (Spanish - Spain, international sort).
Dim myCompIntl As New Comparer(New CultureInfo("es-ES", False))
Console.WriteLine(" International Sort: {0}", myCompIntl.Compare(str1, str2))
' Uses the Comparer based on the culture identifier 0x040A (Spanish - Spain, traditional sort).
Dim myCompTrad As New Comparer(New CultureInfo(&H40A, False))
Console.WriteLine(" Traditional Sort : {0}", myCompTrad.Compare(str1, str2))
End Sub 'Main
End Class 'SamplesComparer
'This code produces the following output.
'
'Comparing "llegar" and "lugar" ...
' Invariant Comparer: -1
' International Sort: -1
' Traditional Sort : 1
using System;
using System.Collections;
using System.Globalization;
public class SamplesComparer {
public static void Main() {
// Creates the strings to compare.
String str1 = "llegar";
String str2 = "lugar";
Console.WriteLine( "Comparing \"{0}\" and \"{1}\" ...", str1, str2 );
// Uses the DefaultInvariant Comparer.
Console.WriteLine( " Invariant Comparer: {0}", Comparer.DefaultInvariant.Compare( str1, str2 ) );
// Uses the Comparer based on the culture "es-ES" (Spanish - Spain, international sort).
Comparer myCompIntl = new Comparer( new CultureInfo( "es-ES", false ) );
Console.WriteLine( " International Sort: {0}", myCompIntl.Compare( str1, str2 ) );
// Uses the Comparer based on the culture identifier 0x040A (Spanish - Spain, traditional sort).
Comparer myCompTrad = new Comparer( new CultureInfo( 0x040A, false ) );
Console.WriteLine( " Traditional Sort : {0}", myCompTrad.Compare( str1, str2 ) );
}
}
/*
This code produces the following output.
Comparing "llegar" and "lugar" ...
Invariant Comparer: -1
International Sort: -1
Traditional Sort : 1
*/
using namespace System;
using namespace System::Collections;
using namespace System::Globalization;
int main()
{
// Creates the strings to compare.
String^ str1 = "llegar";
String^ str2 = "lugar";
Console::WriteLine( "Comparing \"{0}\" and \"{1}\" ...", str1, str2 );
// Uses the DefaultInvariant Comparer.
Console::WriteLine( " Invariant Comparer: {0}", Comparer::DefaultInvariant->Compare( str1, str2 ) );
// Uses the Comparer based on the culture "es-ES" (Spanish - Spain, international sort).
Comparer^ myCompIntl = gcnew Comparer( gcnew CultureInfo( "es-ES",false ) );
Console::WriteLine( " International Sort: {0}", myCompIntl->Compare( str1, str2 ) );
// Uses the Comparer based on the culture identifier 0x040A (Spanish - Spain, traditional sort).
Comparer^ myCompTrad = gcnew Comparer( gcnew CultureInfo( 0x040A,false ) );
Console::WriteLine( " Traditional Sort : {0}", myCompTrad->Compare( str1, str2 ) );
}
/*
This code produces the following output.
Comparing "llegar" and "lugar" ...
Invariant Comparer: -1
International Sort: -1
Traditional Sort : 1
*/
System..::.Object
System.Collections..::.Comparer
Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.
Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98, Windows CE, Windows Mobile for Smartphone, Windows Mobile for Pocket PC, Xbox 360, Zune
The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
.NET Framework
Supported in: 3.5, 3.0, 2.0, 1.1, 1.0
.NET Compact Framework
Supported in: 3.5, 2.0, 1.0
XNA Framework
Supported in: 3.0, 2.0, 1.0
Reference