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.NET Framework Class Library
StringEquals Method (String, String, StringComparison)

Determines whether two specified String objects have the same value. A parameter specifies the culture, case, and sort rules used in the comparison.

Namespace:   System
Assembly:  mscorlib (in mscorlib.dll)
Syntax
Public Shared Function Equals ( _
	a As [%$TOPIC/t4411bks_en-us_VS_110_2_0_0_0_0%], _
	b As [%$TOPIC/t4411bks_en-us_VS_110_2_0_0_0_1%], _
	comparisonType As [%$TOPIC/t4411bks_en-us_VS_110_2_0_0_0_2%] _
) As [%$TOPIC/t4411bks_en-us_VS_110_2_0_0_0_3%]
public static [%$TOPIC/t4411bks_en-us_VS_110_2_0_1_0_0%] Equals(
	[%$TOPIC/t4411bks_en-us_VS_110_2_0_1_0_1%] a,
	[%$TOPIC/t4411bks_en-us_VS_110_2_0_1_0_2%] b,
	[%$TOPIC/t4411bks_en-us_VS_110_2_0_1_0_3%] comparisonType
)
public:
static [%$TOPIC/t4411bks_en-us_VS_110_2_0_2_0_0%] Equals(
	[%$TOPIC/t4411bks_en-us_VS_110_2_0_2_0_1%]^ a, 
	[%$TOPIC/t4411bks_en-us_VS_110_2_0_2_0_2%]^ b, 
	[%$TOPIC/t4411bks_en-us_VS_110_2_0_2_0_3%] comparisonType
)
static member Equals : 
        a:[%$TOPIC/t4411bks_en-us_VS_110_2_0_3_0_0%] * 
        b:[%$TOPIC/t4411bks_en-us_VS_110_2_0_3_0_1%] * 
        comparisonType:[%$TOPIC/t4411bks_en-us_VS_110_2_0_3_0_2%] -> [%$TOPIC/t4411bks_en-us_VS_110_2_0_3_0_3%]

Parameters

a
Type: SystemString

The first string to compare, or .

b
Type: SystemString

The second string to compare, or .

comparisonType
Type: SystemStringComparison

One of the enumeration values that specifies the rules for the comparison.

Return Value

Type: SystemBoolean
true if the value of the a parameter is equal to the value of the b parameter; otherwise, false.
Exceptions
ExceptionCondition
ArgumentException

comparisonType is not a StringComparison value.

Remarks

The comparisonType parameter indicates whether the comparison should use the current or invariant culture, honor or ignore the case of the two strings being compared, or use word or ordinal sort rules.

Examples

The following example compares four sets of words by using each member of the StringComparison enumeration. The comparisons use the conventions of the English (United States) and Sami (Upper Sweden) cultures. Note that the strings "encyclopædia" and "encyclopedia" are considered equivalent in the en-US culture but not in the Sami (Northern Sweden) culture.

Imports System.Globalization
Imports System.Threading

Module Example
   Public Sub Main()
      Dim cultureNames() As String = { "en-US", "se-SE" }
      Dim strings1() As String = { "case",  "encyclopædia",  
                                   "encyclopædia", "Archæology" }
      Dim strings2() As String = { "Case", "encyclopaedia", 
                                   "encyclopedia" , "ARCHÆOLOGY" }
      Dim comparisons() As StringComparison = CType([Enum].GetValues(GetType(StringComparison)),
                                           StringComparison())

      For Each cultureName In cultureNames
         Thread.CurrentThread.CurrentCulture = CultureInfo.CreateSpecificCulture(cultureName)
         Console.WriteLine("Current Culture: {0}", CultureInfo.CurrentCulture.Name)
         For ctr As Integer = 0 To strings1.GetUpperBound(0)
            For Each comparison In comparisons
               Console.WriteLine("   {0} = {1} ({2}): {3}", strings1(ctr),
                                 strings2(ctr), comparison, 
                                 String.Equals(strings1(ctr), strings2(ctr), comparison))
            Next
            Console.WriteLine()         
         Next
         Console.WriteLine()
      Next 
   End Sub 
End Module 
' The example displays the following output: 
'    Current Culture: en-US 
'       case = Case (CurrentCulture): False 
'       case = Case (CurrentCultureIgnoreCase): True 
'       case = Case (InvariantCulture): False 
'       case = Case (InvariantCultureIgnoreCase): True 
'       case = Case (Ordinal): False 
'       case = Case (OrdinalIgnoreCase): True 
'     
'       encyclopædia = encyclopaedia (CurrentCulture): True 
'       encyclopædia = encyclopaedia (CurrentCultureIgnoreCase): True 
'       encyclopædia = encyclopaedia (InvariantCulture): True 
'       encyclopædia = encyclopaedia (InvariantCultureIgnoreCase): True 
'       encyclopædia = encyclopaedia (Ordinal): False 
'       encyclopædia = encyclopaedia (OrdinalIgnoreCase): False 
'     
'       encyclopædia = encyclopedia (CurrentCulture): False 
'       encyclopædia = encyclopedia (CurrentCultureIgnoreCase): False 
'       encyclopædia = encyclopedia (InvariantCulture): False 
'       encyclopædia = encyclopedia (InvariantCultureIgnoreCase): False 
'       encyclopædia = encyclopedia (Ordinal): False 
'       encyclopædia = encyclopedia (OrdinalIgnoreCase): False 
'     
'       Archæology = ARCHÆOLOGY (CurrentCulture): False 
'       Archæology = ARCHÆOLOGY (CurrentCultureIgnoreCase): True 
'       Archæology = ARCHÆOLOGY (InvariantCulture): False 
'       Archæology = ARCHÆOLOGY (InvariantCultureIgnoreCase): True 
'       Archæology = ARCHÆOLOGY (Ordinal): False 
'       Archæology = ARCHÆOLOGY (OrdinalIgnoreCase): True 
'     
'     
'    Current Culture: se-SE 
'       case = Case (CurrentCulture): False 
'       case = Case (CurrentCultureIgnoreCase): True 
'       case = Case (InvariantCulture): False 
'       case = Case (InvariantCultureIgnoreCase): True 
'       case = Case (Ordinal): False 
'       case = Case (OrdinalIgnoreCase): True 
'     
'       encyclopædia = encyclopaedia (CurrentCulture): False 
'       encyclopædia = encyclopaedia (CurrentCultureIgnoreCase): False 
'       encyclopædia = encyclopaedia (InvariantCulture): True 
'       encyclopædia = encyclopaedia (InvariantCultureIgnoreCase): True 
'       encyclopædia = encyclopaedia (Ordinal): False 
'       encyclopædia = encyclopaedia (OrdinalIgnoreCase): False 
'     
'       encyclopædia = encyclopedia (CurrentCulture): False 
'       encyclopædia = encyclopedia (CurrentCultureIgnoreCase): False 
'       encyclopædia = encyclopedia (InvariantCulture): False 
'       encyclopædia = encyclopedia (InvariantCultureIgnoreCase): False 
'       encyclopædia = encyclopedia (Ordinal): False 
'       encyclopædia = encyclopedia (OrdinalIgnoreCase): False 
'     
'       Archæology = ARCHÆOLOGY (CurrentCulture): False 
'       Archæology = ARCHÆOLOGY (CurrentCultureIgnoreCase): True 
'       Archæology = ARCHÆOLOGY (InvariantCulture): False 
'       Archæology = ARCHÆOLOGY (InvariantCultureIgnoreCase): True 
'       Archæology = ARCHÆOLOGY (Ordinal): False 
'       Archæology = ARCHÆOLOGY (OrdinalIgnoreCase): True
using System;
using System.Globalization;
using System.Threading;

public class Example
{
   public static void Main()
   {
      String[] cultureNames = { "en-US", "se-SE" };
      String[] strings1 = { "case",  "encyclopædia",  
                            "encyclopædia", "Archæology" };
      String[] strings2 = { "Case", "encyclopaedia", 
                            "encyclopedia" , "ARCHÆOLOGY" };
      StringComparison[] comparisons = (StringComparison[]) Enum.GetValues(typeof(StringComparison));

      foreach (var cultureName in cultureNames) {
         Thread.CurrentThread.CurrentCulture = CultureInfo.CreateSpecificCulture(cultureName);
         Console.WriteLine("Current Culture: {0}", CultureInfo.CurrentCulture.Name);
         for (int ctr = 0; ctr <= strings1.GetUpperBound(0); ctr++) {
            foreach (var comparison in comparisons) 
               Console.WriteLine("   {0} = {1} ({2}): {3}", strings1[ctr],
                                 strings2[ctr], comparison, 
                                 String.Equals(strings1[ctr], strings2[ctr], comparison));

            Console.WriteLine();         
         }
         Console.WriteLine();
      }
   }
}
// The example displays the following output: 
//    Current Culture: en-US 
//       case = Case (CurrentCulture): False 
//       case = Case (CurrentCultureIgnoreCase): True 
//       case = Case (InvariantCulture): False 
//       case = Case (InvariantCultureIgnoreCase): True 
//       case = Case (Ordinal): False 
//       case = Case (OrdinalIgnoreCase): True 
//     
//       encyclopædia = encyclopaedia (CurrentCulture): True 
//       encyclopædia = encyclopaedia (CurrentCultureIgnoreCase): True 
//       encyclopædia = encyclopaedia (InvariantCulture): True 
//       encyclopædia = encyclopaedia (InvariantCultureIgnoreCase): True 
//       encyclopædia = encyclopaedia (Ordinal): False 
//       encyclopædia = encyclopaedia (OrdinalIgnoreCase): False 
//     
//       encyclopædia = encyclopedia (CurrentCulture): False 
//       encyclopædia = encyclopedia (CurrentCultureIgnoreCase): False 
//       encyclopædia = encyclopedia (InvariantCulture): False 
//       encyclopædia = encyclopedia (InvariantCultureIgnoreCase): False 
//       encyclopædia = encyclopedia (Ordinal): False 
//       encyclopædia = encyclopedia (OrdinalIgnoreCase): False 
//     
//       Archæology = ARCHÆOLOGY (CurrentCulture): False 
//       Archæology = ARCHÆOLOGY (CurrentCultureIgnoreCase): True 
//       Archæology = ARCHÆOLOGY (InvariantCulture): False 
//       Archæology = ARCHÆOLOGY (InvariantCultureIgnoreCase): True 
//       Archæology = ARCHÆOLOGY (Ordinal): False 
//       Archæology = ARCHÆOLOGY (OrdinalIgnoreCase): True 
//     
//     
//    Current Culture: se-SE 
//       case = Case (CurrentCulture): False 
//       case = Case (CurrentCultureIgnoreCase): True 
//       case = Case (InvariantCulture): False 
//       case = Case (InvariantCultureIgnoreCase): True 
//       case = Case (Ordinal): False 
//       case = Case (OrdinalIgnoreCase): True 
//     
//       encyclopædia = encyclopaedia (CurrentCulture): False 
//       encyclopædia = encyclopaedia (CurrentCultureIgnoreCase): False 
//       encyclopædia = encyclopaedia (InvariantCulture): True 
//       encyclopædia = encyclopaedia (InvariantCultureIgnoreCase): True 
//       encyclopædia = encyclopaedia (Ordinal): False 
//       encyclopædia = encyclopaedia (OrdinalIgnoreCase): False 
//     
//       encyclopædia = encyclopedia (CurrentCulture): False 
//       encyclopædia = encyclopedia (CurrentCultureIgnoreCase): False 
//       encyclopædia = encyclopedia (InvariantCulture): False 
//       encyclopædia = encyclopedia (InvariantCultureIgnoreCase): False 
//       encyclopædia = encyclopedia (Ordinal): False 
//       encyclopædia = encyclopedia (OrdinalIgnoreCase): False 
//     
//       Archæology = ARCHÆOLOGY (CurrentCulture): False 
//       Archæology = ARCHÆOLOGY (CurrentCultureIgnoreCase): True 
//       Archæology = ARCHÆOLOGY (InvariantCulture): False 
//       Archæology = ARCHÆOLOGY (InvariantCultureIgnoreCase): True 
//       Archæology = ARCHÆOLOGY (Ordinal): False 
//       Archæology = ARCHÆOLOGY (OrdinalIgnoreCase): True
Version Information

.NET Framework

Supported in: 4.5.1, 4.5, 4, 3.5, 3.0, 2.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Portable Class Library

Supported in: Portable Class Library

.NET for Windows Store apps

Supported in: Windows 8

.NET for Windows Phone apps

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

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.