CaseInsensitiveHashCodeProvider Constructors

Definition

Initializes a new instance of the CaseInsensitiveHashCodeProvider class.

Overloads

CaseInsensitiveHashCodeProvider()

Initializes a new instance of the CaseInsensitiveHashCodeProvider class using the CurrentCulture of the current thread.

CaseInsensitiveHashCodeProvider(CultureInfo)

Initializes a new instance of the CaseInsensitiveHashCodeProvider class using the specified CultureInfo.

CaseInsensitiveHashCodeProvider()

Source:
CaseInsensitiveHashCodeProvider.cs
Source:
CaseInsensitiveHashCodeProvider.cs
Source:
CaseInsensitiveHashCodeProvider.cs

Initializes a new instance of the CaseInsensitiveHashCodeProvider class using the CurrentCulture of the current thread.

C#
public CaseInsensitiveHashCodeProvider();

Examples

The following code example creates a case-sensitive hash table and a case-insensitive hash table and demonstrates the difference in their behavior, even if both contain the same elements.

C#
using System;
using System.Collections;
using System.Globalization;

public class SamplesHashtable  {

   public static void Main()  {

      // Create a Hashtable using the default hash code provider and the default comparer.
      Hashtable myHT1 = new Hashtable();
      myHT1.Add("FIRST", "Hello");
      myHT1.Add("SECOND", "World");
      myHT1.Add("THIRD", "!");

      // Create a Hashtable using a case-insensitive code provider and a case-insensitive comparer,
      // based on the culture of the current thread.
      Hashtable myHT2 = new Hashtable( new CaseInsensitiveHashCodeProvider(), new CaseInsensitiveComparer() );
      myHT2.Add("FIRST", "Hello");
      myHT2.Add("SECOND", "World");
      myHT2.Add("THIRD", "!");

      // Create a Hashtable using a case-insensitive code provider and a case-insensitive comparer,
      // based on the InvariantCulture.
      Hashtable myHT3 = new Hashtable( CaseInsensitiveHashCodeProvider.DefaultInvariant, CaseInsensitiveComparer.DefaultInvariant );
      myHT3.Add("FIRST", "Hello");
      myHT3.Add("SECOND", "World");
      myHT3.Add("THIRD", "!");

      // Create a Hashtable using a case-insensitive code provider and a case-insensitive comparer,
      // based on the Turkish culture (tr-TR), where "I" is not the uppercase version of "i".
      CultureInfo myCul = new CultureInfo( "tr-TR" );
      Hashtable myHT4 = new Hashtable( new CaseInsensitiveHashCodeProvider( myCul ), new CaseInsensitiveComparer( myCul ) );
      myHT4.Add("FIRST", "Hello");
      myHT4.Add("SECOND", "World");
      myHT4.Add("THIRD", "!");

      // Search for a key in each hashtable.
      Console.WriteLine( "first is in myHT1: {0}", myHT1.ContainsKey( "first" ) );
      Console.WriteLine( "first is in myHT2: {0}", myHT2.ContainsKey( "first" ) );
      Console.WriteLine( "first is in myHT3: {0}", myHT3.ContainsKey( "first" ) );
      Console.WriteLine( "first is in myHT4: {0}", myHT4.ContainsKey( "first" ) );
   }
}


/*
This code produces the following output.  Results vary depending on the system's culture settings.

first is in myHT1: False
first is in myHT2: True
first is in myHT3: True
first is in myHT4: False

*/

Remarks

When the CaseInsensitiveHashCodeProvider instance is created using this constructor, the Thread.CurrentCulture of the current thread is saved. Comparison procedures use the saved culture to determine the casing rules; therefore, hash code 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.

See also

Applies to

.NET 9 and other versions
Product Versions
.NET Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9
.NET Framework 1.1, 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1
.NET Standard 2.0, 2.1

CaseInsensitiveHashCodeProvider(CultureInfo)

Source:
CaseInsensitiveHashCodeProvider.cs
Source:
CaseInsensitiveHashCodeProvider.cs
Source:
CaseInsensitiveHashCodeProvider.cs

Initializes a new instance of the CaseInsensitiveHashCodeProvider class using the specified CultureInfo.

C#
public CaseInsensitiveHashCodeProvider(System.Globalization.CultureInfo culture);

Parameters

culture
CultureInfo

The CultureInfo to use for the new CaseInsensitiveHashCodeProvider.

Exceptions

culture is null.

Examples

The following code example creates a case-sensitive hash table and a case-insensitive hash table and demonstrates the difference in their behavior, even if both contain the same elements.

C#
using System;
using System.Collections;
using System.Globalization;

public class SamplesHashtable  {

   public static void Main()  {

      // Create a Hashtable using the default hash code provider and the default comparer.
      Hashtable myHT1 = new Hashtable();
      myHT1.Add("FIRST", "Hello");
      myHT1.Add("SECOND", "World");
      myHT1.Add("THIRD", "!");

      // Create a Hashtable using a case-insensitive code provider and a case-insensitive comparer,
      // based on the culture of the current thread.
      Hashtable myHT2 = new Hashtable( new CaseInsensitiveHashCodeProvider(), new CaseInsensitiveComparer() );
      myHT2.Add("FIRST", "Hello");
      myHT2.Add("SECOND", "World");
      myHT2.Add("THIRD", "!");

      // Create a Hashtable using a case-insensitive code provider and a case-insensitive comparer,
      // based on the InvariantCulture.
      Hashtable myHT3 = new Hashtable( CaseInsensitiveHashCodeProvider.DefaultInvariant, CaseInsensitiveComparer.DefaultInvariant );
      myHT3.Add("FIRST", "Hello");
      myHT3.Add("SECOND", "World");
      myHT3.Add("THIRD", "!");

      // Create a Hashtable using a case-insensitive code provider and a case-insensitive comparer,
      // based on the Turkish culture (tr-TR), where "I" is not the uppercase version of "i".
      CultureInfo myCul = new CultureInfo( "tr-TR" );
      Hashtable myHT4 = new Hashtable( new CaseInsensitiveHashCodeProvider( myCul ), new CaseInsensitiveComparer( myCul ) );
      myHT4.Add("FIRST", "Hello");
      myHT4.Add("SECOND", "World");
      myHT4.Add("THIRD", "!");

      // Search for a key in each hashtable.
      Console.WriteLine( "first is in myHT1: {0}", myHT1.ContainsKey( "first" ) );
      Console.WriteLine( "first is in myHT2: {0}", myHT2.ContainsKey( "first" ) );
      Console.WriteLine( "first is in myHT3: {0}", myHT3.ContainsKey( "first" ) );
      Console.WriteLine( "first is in myHT4: {0}", myHT4.ContainsKey( "first" ) );
   }
}


/*
This code produces the following output.  Results vary depending on the system's culture settings.

first is in myHT1: False
first is in myHT2: True
first is in myHT3: True
first is in myHT4: False

*/

Remarks

Comparison procedures use the specified System.Globalization.CultureInfo to determine the casing rules. Hash code 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.

See also

Applies to

.NET 9 and other versions
Product Versions
.NET Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9
.NET Framework 1.1, 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1
.NET Standard 2.0, 2.1