Comparer.Compare(Object, Object) Method

public:
 virtual int Compare(System::Object ^ a, System::Object ^ b);

public int Compare (object a, object b);

public int Compare (object? a, object? b);

abstract member Compare : obj * obj -> int
override this.Compare : obj * obj -> int

Public Function Compare (a As Object, b As Object) As Integer

Parameters

Returns

A signed integer that indicates the relative values of a and b, as shown in the following table.

Implements

Exceptions

Examples

The following code example shows how Compare returns different values depending on the culture associated with the Comparer.

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

*/

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

*/

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

End Class


'This code produces the following output.
'
'Comparing "llegar" and "lugar" ...
'   Invariant Comparer: -1
'   International Sort: -1
'   Traditional Sort  : 1

Remarks

If a implements IComparable, then a. CompareTo (b) is returned; otherwise, if b implements IComparable, then the negated result of b. CompareTo (a) is returned.

Comparing null with any type is allowed and does not generate an exception when using IComparable. When sorting, null is considered to be less than any other object.

String comparisons might have different results depending on the culture. For more information on culture-specific comparisons, see the System.Globalization namespace and Globalization and Localization.

Applies to

See also

• IComparable
• CompareInfo
• CurrentCulture
• CultureInfo