CompareInfo Class
Implements a set of methods for culture-sensitive string comparisons.
Assembly: mscorlib (in mscorlib.dll)
The CultureInfo class includes a CompareInfo property that is an instance of this class. String.Compare uses the information in CultureInfo.CompareInfo to compare strings.
CompareInfo provides the GetCompareInfo method, instead of public constructors, to allow for late-bound access.
To create a CompareInfo object for any culture, the application should use the CultureInfo.CompareInfo property, or use the GetCompareInfo method.
Ignored Search Values
Comparison operations, such as those performed by the IndexOf or LastIndexOf methods, can yield unexpected results if the value to search for is ignored. The search value is ignored if it is an empty string (""), a character or string consisting of characters having code points that are not considered in the operation because of comparison options, or a value with code points that have no linguistic significance. If the search value for the IndexOf method is an empty string, for example, the return value is zero.
Security Considerations
If a security decision depends on a string comparison or a case change, the application should use the InvariantCulture to ensure that the behavior is consistent, regardless of the culture settings of the operating system.
The following code example shows how the CompareInfo object associated with a CultureInfo object affects string comparison.
Imports System Imports System.Text Imports System.Globalization NotInheritable Public Class App Shared Sub Main(ByVal args() As String) Dim sign() As String = {"<", "=", ">"} ' The code below demonstrates how strings compare ' differently for different cultures. Dim s1 As String = "Coté" Dim s2 As String = "coté" Dim s3 As String = "côte" ' Set sort order of strings for French in France. Dim ci As CompareInfo = New CultureInfo("fr-FR").CompareInfo Console.WriteLine("The LCID for {0} is {1}.", ci.Name, ci.LCID) ' Display the result using fr-FR Compare of Coté = coté. Console.WriteLine("fr-FR Compare: {0} {2} {1}", _ s1, s2, sign((ci.Compare(s1, s2, CompareOptions.IgnoreCase) + 1))) ' Display the result using fr-FR Compare of coté > côte. Console.WriteLine("fr-FR Compare: {0} {2} {1}", _ s2, s3, sign((ci.Compare(s2, s3, CompareOptions.None) + 1))) ' Set sort order of strings for Japanese as spoken in Japan. ci = New CultureInfo("ja-JP").CompareInfo Console.WriteLine("The LCID for {0} is {1}.", ci.Name, ci.LCID) ' Display the result using ja-JP Compare of coté < côte. Console.WriteLine("ja-JP Compare: {0} {2} {1}", _ s2, s3, sign((ci.Compare(s2, s3) + 1))) End Sub 'Main End Class 'App ' This code produces the following output. ' ' The LCID for fr-FR is 1036. ' fr-FR Compare: Coté = coté ' fr-FR Compare: coté > côte ' The LCID for ja-JP is 1041. ' ja-JP Compare: coté < côte
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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.