Comparer::Compare Method (Object^, Object^)


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Performs a case-sensitive comparison of two objects of the same type and returns a value indicating whether one is less than, equal to, or greater than the other.

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

virtual int Compare(
	Object^ a,
	Object^ b
) sealed


Type: System::Object^

The first object to compare.

Type: System::Object^

The second object to compare.

Return Value

Type: System::Int32

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



Less than zero

a is less than b.


a equals b.

Greater than zero

a is greater than b.

Exception Condition

Neither a nor b implements the IComparable interface.


a and b are of different types and neither one can handle comparisons with the other.

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 Globalizing and Localizing .NET Framework Applications.

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


Universal Windows Platform
Available since 10
.NET Framework
Available since 1.1
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