String.Equals メソッド (String, String)

2008-03-28

指定した 2 つの String オブジェクトの値が同一かどうかを判断します。

Overloads Public Shared Function Equals( _
   ByVal a As String, _   ByVal b As String _) As Boolean
[C#]
public static bool Equals(stringa,stringb);
[C++]
public: static bool Equals(String* a,String* b);
[JScript]
public static function Equals(
   a : String,b : String) : Boolean;

パラメータ

a
String または null 参照 (Visual Basic では Nothing) 。
b
String または null 参照 (Visual Basic では Nothing) 。

戻り値

a の値が b の値と同じ場合は true 。それ以外の場合は false 。

解説

このメソッドは、序数 (大文字/小文字を区別し、カルチャに依存しない) 比較を実行します。

使用例

 
' Sample for String.Equals(Object)
'            String.Equals(String)
'            String.Equals(String, String)
Imports System
Imports System.Text

Class Sample
   Public Shared Sub Main()
      Dim sb As New StringBuilder("abcd")
      Dim str1 As [String] = "abcd"
      Dim str2 As [String] = Nothing
      Dim o2 As [Object] = Nothing
      
      Console.WriteLine()
      Console.WriteLine(" *  The value of String str1 is '{0}'.", str1)
      Console.WriteLine(" *  The value of StringBuilder sb is '{0}'.", sb.ToString())
      
      Console.WriteLine()
      Console.WriteLine("1a) String.Equals(Object). Object is a StringBuilder, not a String.")
      Console.WriteLine("    Is str1 equal to sb?: {0}", str1.Equals(sb))
      
      Console.WriteLine()
      Console.WriteLine("1b) String.Equals(Object). Object is a String.")
      str2 = sb.ToString()
      o2 = str2
      Console.WriteLine(" *  The value of Object o2 is '{0}'.", o2)
      Console.WriteLine("    Is str1 equal to o2?: {0}", str1.Equals(o2))
      
      Console.WriteLine()
      Console.WriteLine(" 2) String.Equals(String)")
      Console.WriteLine(" *  The value of String str2 is '{0}'.", str2)
      Console.WriteLine("    Is str1 equal to str2?: {0}", str1.Equals(str2))
      
      Console.WriteLine()
      Console.WriteLine(" 3) String.Equals(String, String)")
      Console.WriteLine("    Is str1 equal to str2?: {0}", [String].Equals(str1, str2))
   End Sub 'Main
End Class 'Sample
'
'This example produces the following results:
'
' *  The value of String str1 is 'abcd'.
' *  The value of StringBuilder sb is 'abcd'.
'
'1a) String.Equals(Object). Object is a StringBuilder, not a String.
'    Is str1 equal to sb?: False
'
'1b) String.Equals(Object). Object is a String.
' *  The value of Object o2 is 'abcd'.
'    Is str1 equal to o2?: True
'
' 2) String.Equals(String)
' *  The value of String str2 is 'abcd'.
'    Is str1 equal to str2?: True
'
' 3) String.Equals(String, String)
'    Is str1 equal to str2?: True
'

[C#] 
// Sample for String.Equals(Object)
//            String.Equals(String)
//            String.Equals(String, String)
using System;
using System.Text;

class Sample {
    public static void Main() {
    StringBuilder sb = new StringBuilder("abcd");
    String      str1 = "abcd";
    String      str2 = null;
    Object    o2   = null;

    Console.WriteLine();
    Console.WriteLine(" *  The value of String str1 is '{0}'.", str1);
    Console.WriteLine(" *  The value of StringBuilder sb is '{0}'.", sb.ToString());

    Console.WriteLine();
    Console.WriteLine("1a) String.Equals(Object). Object is a StringBuilder, not a String.");
    Console.WriteLine("    Is str1 equal to sb?: {0}", str1.Equals(sb));

    Console.WriteLine();
    Console.WriteLine("1b) String.Equals(Object). Object is a String.");
    str2 = sb.ToString();
    o2   = str2;
    Console.WriteLine(" *  The value of Object o2 is '{0}'.", o2);
    Console.WriteLine("    Is str1 equal to o2?: {0}", str1.Equals(o2));

    Console.WriteLine();
    Console.WriteLine(" 2) String.Equals(String)");
    Console.WriteLine(" *  The value of String str2 is '{0}'.", str2);
    Console.WriteLine("    Is str1 equal to str2?: {0}", str1.Equals(str2));

    Console.WriteLine();
    Console.WriteLine(" 3) String.Equals(String, String)");
    Console.WriteLine("    Is str1 equal to str2?: {0}", String.Equals(str1, str2));
    }
}
/*
This example produces the following results:

 *  The value of String str1 is 'abcd'.
 *  The value of StringBuilder sb is 'abcd'.

1a) String.Equals(Object). Object is a StringBuilder, not a String.
    Is str1 equal to sb?: False

1b) String.Equals(Object). Object is a String.
 *  The value of Object o2 is 'abcd'.
    Is str1 equal to o2?: True

 2) String.Equals(String)
 *  The value of String str2 is 'abcd'.
    Is str1 equal to str2?: True

 3) String.Equals(String, String)
    Is str1 equal to str2?: True
*/

[C++] 
// Sample for String::Equals(Object)
//            String::Equals(String)
//            String::Equals(String, String)
#using <mscorlib.dll>

using namespace System;
using namespace System::Text;

int main() {
    StringBuilder* sb = new StringBuilder(S"abcd");
    String* str1 = S"abcd";
    String* str2 = 0;
    Object* o2 = 0;

    Console::WriteLine();
    Console::WriteLine(S" *  The value of String str1 is '{0}'.", str1);
    Console::WriteLine(S" *  The value of StringBuilder sb is '{0}'.", sb);

    Console::WriteLine();
    Console::WriteLine(S"1a) String::Equals(Object). Object is a StringBuilder, not a String.");
    Console::WriteLine(S"    Is str1 equal to sb?: {0}", __box(str1->Equals(sb)));

    Console::WriteLine();
    Console::WriteLine(S"1b) String::Equals(Object). Object is a String.");
    str2 = sb->ToString();
    o2   = str2;
    Console::WriteLine(S" *  The value of Object o2 is '{0}'.", o2);
    Console::WriteLine(S"    Is str1 equal to o2?: {0}", __box(str1->Equals(o2)));

    Console::WriteLine();
    Console::WriteLine(S" 2) String::Equals(String)");
    Console::WriteLine(S" *  The value of String str2 is '{0}'.", str2);
    Console::WriteLine(S"    Is str1 equal to str2?: {0}", __box(str1->Equals(str2)));

    Console::WriteLine();
    Console::WriteLine(S" 3) String::Equals(String, String)");
    Console::WriteLine(S"    Is str1 equal to str2?: {0}", __box(String::Equals(str1, str2)));
}
/*
This example produces the following results:

 *  The value of String str1 is 'abcd'.
 *  The value of StringBuilder sb is 'abcd'.

1a) String::Equals(Object). Object is a StringBuilder, not a String.
    Is str1 equal to sb?: False

1b) String::Equals(Object). Object is a String.
 *  The value of Object o2 is 'abcd'.
    Is str1 equal to o2?: True

 2) String::Equals(String)
 *  The value of String str2 is 'abcd'.
    Is str1 equal to str2?: True

 3) String::Equals(String, String)
    Is str1 equal to str2?: True
*/

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必要条件

プラットフォーム: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 ファミリ, .NET Compact Framework - Windows CE .NET, Common Language Infrastructure (CLI) Standard

参照

String クラス | String メンバ | System 名前空間 | String.Equals オーバーロードの一覧 | CompareOrdinal

次の方法で共有

String.Equals メソッド (String, String)

パラメータ

戻り値

解説

使用例

必要条件

参照

その他のリソース