String.GetHashCode メソッド

.NET Framework クラス ライブラリ リファレンス

String.GetHashCode メソッド

この文字列のハッシュ コードを返します。

名前空間: System
アセンブリ: mscorlib (mscorlib.dll 内)
構文

Visual Basic (宣言)

Public Overrides Function
 GetHashCode As Integer

Visual Basic (使用法)

Dim instance As String
Dim returnValue As Integer

returnValue = instance.GetHashCode

C#

public override int GetHashCode ()

C++

public:
virtual int GetHashCode () override

J#

public int GetHashCode ()

JScript

public override function GetHashCode () : int

戻り値
32 ビット符号付き整数ハッシュ コード。

解説

GetHashCode の動作は実装に依存します。この実装は、共通言語ランタイムのあるバージョンから別のバージョンに変更される可能性があります。GetHashCode のパフォーマンス向上がその理由です。GetHashCode の動作を一定にする必要がある場合は、GetHashCode のランタイムによる実装を、変更されないことがわかっている独自の実装でオーバーライドしてください。

使用例

さまざまな入力文字列を使用する GetHashCode メソッドのコード例を次に示します。

Visual Basic

' Example for the String.GetHashCode( ) method.
Imports System
Imports Microsoft.VisualBasic

Module GetHashCode
   
    Sub Main()
        Console.WriteLine( _
            "This example of String.GetHashCode( ) "
 & _
            "generates the following output." &
 vbCrLf)

        DisplayHashCode("")
        DisplayHashCode("a")
        DisplayHashCode("ab")
        DisplayHashCode("abc")
        DisplayHashCode("abd")
        DisplayHashCode("abe")
        DisplayHashCode("abcdef")
        DisplayHashCode("abcdeg")
        DisplayHashCode("abcdeh")
        DisplayHashCode("abcdei")
        DisplayHashCode("Abcdeg")
        DisplayHashCode("Abcdeh")
        DisplayHashCode("Abcdei")
    End Sub 'Main
       
    Sub DisplayHashCode(Operand As String)

        Dim HashCode As Integer
 = Operand.GetHashCode()
        Console.WriteLine( _
            "The hash code for ""{0}""
 is: 0x{1:X8}, {1}", _
            Operand, HashCode)

    End Sub 'DisplayHashCode
End Module 'GetHashCode

' This example of String.GetHashCode( ) generates the following output.
' 
' The hash code for "" is: 0x00001505, 5381
' The hash code for "a" is: 0x0002B5C4, 177604
' The hash code for "ab" is: 0x00596E26, 5860902
' The hash code for "abc" is: 0x0B873285, 193409669
' The hash code for "abd" is: 0x0B873282, 193409666
' The hash code for "abe" is: 0x0B873283, 193409667
' The hash code for "abcdef" is: 0x4DDB4BE2, 1306217442
' The hash code for "abcdeg" is: 0x4DDB4BE3, 1306217443
' The hash code for "abcdeh" is: 0x4DDB4BEC, 1306217452
' The hash code for "abcdei" is: 0x4DDB4BED, 1306217453
' The hash code for "Abcdeg" is: 0x941C4FC3, -1810083901
' The hash code for "Abcdeh" is: 0x941C4FCC, -1810083892
' The hash code for "Abcdei" is: 0x941C4FCD, -1810083891

C#

// Example for the String.GetHashCode( ) method.
using System;

class GetHashCode 
{
    public static void Main()
 
    {
        Console.WriteLine( 
            "This example of String.GetHashCode( ) " +
            "generates the following output.\n" );

        DisplayHashCode( "" );
        DisplayHashCode( "a" );
        DisplayHashCode( "ab" );
        DisplayHashCode( "abc" );
        DisplayHashCode( "abd" );
        DisplayHashCode( "abe" );
        DisplayHashCode( "abcdef" );
        DisplayHashCode( "abcdeg" );
        DisplayHashCode( "abcdeh" );
        DisplayHashCode( "abcdei" );
        DisplayHashCode( "Abcdeg" );
        DisplayHashCode( "Abcdeh" );
        DisplayHashCode( "Abcdei" );
    }

    static void DisplayHashCode( String Operand
 )
    {
        int     HashCode = Operand.GetHashCode( );
        Console.WriteLine( 
            "The hash code for \"{0}\" is: 0x{1:X8},
 {1}",
            Operand, HashCode );
    }
}

/*
This example of String.GetHashCode( ) generates the following output.

The hash code for "" is: 0x00001505, 5381
The hash code for "a" is: 0x0002B5C4, 177604
The hash code for "ab" is: 0x00596E26, 5860902
The hash code for "abc" is: 0x0B873285, 193409669
The hash code for "abd" is: 0x0B873282, 193409666
The hash code for "abe" is: 0x0B873283, 193409667
The hash code for "abcdef" is: 0x4DDB4BE2, 1306217442
The hash code for "abcdeg" is: 0x4DDB4BE3, 1306217443
The hash code for "abcdeh" is: 0x4DDB4BEC, 1306217452
The hash code for "abcdei" is: 0x4DDB4BED, 1306217453
The hash code for "Abcdeg" is: 0x941C4FC3, -1810083901
The hash code for "Abcdeh" is: 0x941C4FCC, -1810083892
The hash code for "Abcdei" is: 0x941C4FCD, -1810083891
*/

C++

// Example for the String::GetHashCode( ) method.
using namespace System;
void DisplayHashCode( String^ Operand )
{
   int HashCode = Operand->GetHashCode();
   Console::WriteLine( "The hash code for \"{0}\"
 is: 0x{1:X8}, {1}", Operand, HashCode );
}

int main()
{
   Console::WriteLine( "This example of String::GetHashCode( ) "
   "generates the following output.\n" );
   DisplayHashCode( "" );
   DisplayHashCode( "a" );
   DisplayHashCode( "ab" );
   DisplayHashCode( "abc" );
   DisplayHashCode( "abd" );
   DisplayHashCode( "abe" );
   DisplayHashCode( "abcdef" );
   DisplayHashCode( "abcdeg" );
   DisplayHashCode( "abcdeh" );
   DisplayHashCode( "abcdei" );
   DisplayHashCode( "Abcdeg" );
   DisplayHashCode( "Abcdeh" );
   DisplayHashCode( "Abcdei" );
}

/*
This example of String::GetHashCode( ) generates the following output.

The hash code for "" is: 0x00001505, 5381
The hash code for "a" is: 0x0002B5C4, 177604
The hash code for "ab" is: 0x00596E26, 5860902
The hash code for "abc" is: 0x0B873285, 193409669
The hash code for "abd" is: 0x0B873282, 193409666
The hash code for "abe" is: 0x0B873283, 193409667
The hash code for "abcdef" is: 0x4DDB4BE2, 1306217442
The hash code for "abcdeg" is: 0x4DDB4BE3, 1306217443
The hash code for "abcdeh" is: 0x4DDB4BEC, 1306217452
The hash code for "abcdei" is: 0x4DDB4BED, 1306217453
The hash code for "Abcdeg" is: 0x941C4FC3, -1810083901
The hash code for "Abcdeh" is: 0x941C4FCC, -1810083892
The hash code for "Abcdei" is: 0x941C4FCD, -1810083891
*/

J#

// Example for the String.GetHashCode( ) method.
import System.*;

class GetHashCode
{
    public static void main(String[]
 args)
    {
        Console.WriteLine(("This example of String.GetHashCode( ) " 
            + "generates the following output.\n"));
        DisplayHashCode("");
        DisplayHashCode("a");
        DisplayHashCode("ab");
        DisplayHashCode("abc");
        DisplayHashCode("abd");
        DisplayHashCode("abe");
        DisplayHashCode("abcdef");
        DisplayHashCode("abcdeg");
        DisplayHashCode("abcdeh");
        DisplayHashCode("abcdei");
        DisplayHashCode("Abcdeg");
        DisplayHashCode("Abcdeh");
        DisplayHashCode("Abcdei");
    } //main

    static void DisplayHashCode(String operand)
    {
        int hashCode = operand.GetHashCode();
        Console.WriteLine("The hash code for \"{0}\"
 is: 0x{1}, {2}", 
            operand, ((System.Int32)hashCode).ToString("X8"), 
            ((System.Int32)hashCode).ToString(""));
    } //DisplayHashCode
} //GetHashCode

/*
This example of String.GetHashCode( ) generates the following output.

The hash code for "" is: 0x00001505, 5381
The hash code for "a" is: 0x0002B5C4, 177604
The hash code for "ab" is: 0x00596E26, 5860902
The hash code for "abc" is: 0x0B873285, 193409669
The hash code for "abd" is: 0x0B873282, 193409666
The hash code for "abe" is: 0x0B873283, 193409667
The hash code for "abcdef" is: 0x4DDB4BE2, 1306217442
The hash code for "abcdeg" is: 0x4DDB4BE3, 1306217443
The hash code for "abcdeh" is: 0x4DDB4BEC, 1306217452
The hash code for "abcdei" is: 0x4DDB4BED, 1306217453
The hash code for "Abcdeg" is: 0x941C4FC3, -1810083901
The hash code for "Abcdeh" is: 0x941C4FCC, -1810083892
The hash code for "Abcdei" is: 0x941C4FCD, -1810083891
*/

プラットフォーム

Windows 98, Windows 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

開発プラットフォームの中には、.NET Framework によってサポートされていないバージョンがあります。サポートされているバージョンについては、「システム要件」を参照してください。

バージョン情報

.NET Framework
サポート対象 : 2.0、1.1、1.0
.NET Compact Framework
サポート対象 : 2.0、1.0

参照

関連項目
String クラス
String メンバ
System 名前空間
Int32 構造体