String.Equals Metodo

Riferimento

Definizione

Spazio dei nomi:: System

Assembly:: System.Runtime.dll

Assembly:: mscorlib.dll

Assembly:: netstandard.dll

Importante

Alcune informazioni sono relative alla release non definitiva del prodotto, che potrebbe subire modifiche significative prima della release definitiva. Microsoft non riconosce alcuna garanzia, espressa o implicita, in merito alle informazioni qui fornite.

Determina se due oggetti String hanno lo stesso valore.

Overload

Equals(Object)	Determina se questa istanza e un oggetto specificato, che deve essere anche un oggetto String, hanno lo stesso valore.
Equals(String)	Determina se questa istanza e un altro oggetto String specificato hanno lo stesso valore.
Equals(String, String)	Determina se due oggetti String specificati hanno lo stesso valore.
Equals(String, StringComparison)	Determina se questa stringa e un oggetto String specificato hanno lo stesso valore. Un parametro specifica le impostazioni cultura, l'eventuale distinzione fra maiuscole e minuscole e le regole di ordinamento usate per effettuare il confronto.
Equals(String, String, StringComparison)	Determina se due oggetti String specificati hanno lo stesso valore. Un parametro specifica le impostazioni cultura, l'eventuale distinzione fra maiuscole e minuscole e le regole di ordinamento usate per effettuare il confronto.

Equals(Object)

Source:: String.Comparison.cs

Source:: String.Comparison.cs

Source:: String.Comparison.cs

Determina se questa istanza e un oggetto specificato, che deve essere anche un oggetto String, hanno lo stesso valore.

public:
 override bool Equals(System::Object ^ obj);

public override bool Equals (object obj);

public override bool Equals (object? obj);

override this.Equals : obj -> bool

Public Overrides Function Equals (obj As Object) As Boolean

Parametri

obj: Object

Stringa da confrontare con questa istanza.

Restituisce

Boolean

true se il parametro obj è un oggetto String e il relativo valore corrisponde a quello di questa istanza; in caso contrario, false. Se obj è null, il metodo restituisce false.

Esempio

Nell'esempio seguente viene illustrato il Equals metodo.

// Sample for String::Equals(Object)
//            String::Equals(String)
//            String::Equals(String, String)
using namespace System;
using namespace System::Text;
int main()
{
   StringBuilder^ sb = gcnew StringBuilder( "abcd" );
   String^ str1 = "abcd";
   String^ str2 = nullptr;
   Object^ o2 = nullptr;
   Console::WriteLine();
   Console::WriteLine( " *  The value of String str1 is '{0}'.", str1 );
   Console::WriteLine( " *  The value of StringBuilder sb is '{0}'.", sb );
   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
*/

// Sample for String.Equals(Object)
//            String.Equals(String)
//            String.Equals(String, String)
using System;
using System.Text;

class Sample1
{
    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
*/

// Sample for String.Equals(Object)
//            String.Equals(String)
//            String.Equals(String, String)
open System
open System.Text

let sb = StringBuilder "abcd"
let str1 = "abcd"
let str2 = string sb
let o2: obj = str2

printfn $"""
*  The value of String str1 is '{str1}'.
*  The value of StringBuilder sb is '{sb}'.

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

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

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

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

' Sample for String.Equals(Object)
'            String.Equals(String)
'            String.Equals(String, String)
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
End Class
'
'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
'

Commenti

Questo metodo esegue un confronto ordinale (con distinzione tra maiuscole e minuscole e senza distinzione tra impostazioni cultura).

Vedi anche

Si applica a

Equals(String)

Source:: String.Comparison.cs

Source:: String.Comparison.cs

Source:: String.Comparison.cs

Determina se questa istanza e un altro oggetto String specificato hanno lo stesso valore.

public:
 virtual bool Equals(System::String ^ value);

public:
 bool Equals(System::String ^ value);

public bool Equals (string value);

public bool Equals (string? value);

override this.Equals : string -> bool

Public Function Equals (value As String) As Boolean

Parametri

value: String

Stringa da confrontare con questa istanza.

Restituisce

Boolean

true se il valore del parametro value è lo stesso di quello di questa istanza; in caso contrario, false. Se value è null, il metodo restituisce false.

Implementazioni

Equals(T)

Esempio

Nell'esempio seguente viene illustrato il Equals metodo. Confronta la parola con maiuscole e minuscole latine "File" con una parola equivalente, l'equivalente minuscolo, l'equivalente maiuscolo e una parola che contiene LETTERE MINUSCOLE LATINE I (U+0131) anziché LATIN SMALL LETTER I (U+0069). Poiché il Equals(String) metodo esegue un confronto ordinale, solo il confronto con una parola identica restituisce true.

using System;

public class Example
{
    public static void Main()
    {
        Console.OutputEncoding = System.Text.Encoding.UTF8;
        string word = "File";
        string[] others = { word.ToLower(), word, word.ToUpper(), "Fıle" };
        foreach (string other in others)
        {
            if (word.Equals(other))
                Console.WriteLine("{0} = {1}", word, other);
            else
                Console.WriteLine("{0} {1} {2}", word, '\u2260', other);
        }
    }
}
// The example displays the following output:
//       File ≠ file
//       File = File
//       File ≠ FILE
//       File ≠ Fıle

open System

Console.OutputEncoding <- Text.Encoding.UTF8
let word = "File"
let others = [| word.ToLower(); word; word.ToUpper(); "Fıle" |]
for other in others do
    if word.Equals other then
        printfn $"{word} = {other}"
    else
        printfn $"{word} \u2260 {other}"
// The example displays the following output:
//       File ≠ file
//       File = File
//       File ≠ FILE
//       File ≠ Fıle

Module Example
   Public Sub Main()
      Console.OutputEncoding = System.Text.Encoding.UTF8
      
      Dim word As String = "File"
      Dim others() As String = { word.ToLower(), word, word.ToUpper(), _
                                 "Fıle" }
      For Each other As String In others
         If word.Equals(other) Then 
            Console.WriteLine("{0} = {1}", word, other)
         Else
            Console.WriteLine("{0} {1} {2}", word, ChrW(&H2260), other)
         End If      
      Next        
   End Sub
End Module
' The example displays the following output:
'       File ≠ file
'       File = File
'       File ≠ FILE
'       File ≠ Fıle

Commenti

Questo metodo esegue un confronto ordinale (con distinzione tra maiuscole e minuscole e senza distinzione tra impostazioni cultura).

Vedi anche

CompareOrdinal(String, String)

Si applica a

Equals(String, String)

Source:: String.Comparison.cs

Source:: String.Comparison.cs

Source:: String.Comparison.cs

Determina se due oggetti String specificati hanno lo stesso valore.

public:
 static bool Equals(System::String ^ a, System::String ^ b);

public static bool Equals (string a, string b);

public static bool Equals (string? a, string? b);

static member Equals : string * string -> bool

Public Shared Function Equals (a As String, b As String) As Boolean

Parametri

a: String

Prima stringa da confrontare o null.

b: String

Seconda stringa da confrontare o null.

Restituisce

Boolean

true se il valore di a è uguale al valore di b; in caso contrario, false. Se entrambi i parametri a e b sono null, il metodo restituisce true.

Esempio

Nell'esempio seguente viene illustrato il Equals metodo.

// Sample for String::Equals(Object)
//            String::Equals(String)
//            String::Equals(String, String)
using namespace System;
using namespace System::Text;
int main()
{
   StringBuilder^ sb = gcnew StringBuilder( "abcd" );
   String^ str1 = "abcd";
   String^ str2 = nullptr;
   Object^ o2 = nullptr;
   Console::WriteLine();
   Console::WriteLine( " *  The value of String str1 is '{0}'.", str1 );
   Console::WriteLine( " *  The value of StringBuilder sb is '{0}'.", sb );
   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
*/

// Sample for String.Equals(Object)
//            String.Equals(String)
//            String.Equals(String, String)
using System;
using System.Text;

class Sample1
{
    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
*/

// Sample for String.Equals(Object)
//            String.Equals(String)
//            String.Equals(String, String)
open System
open System.Text

let sb = StringBuilder "abcd"
let str1 = "abcd"
let str2 = string sb
let o2: obj = str2

printfn $"""
*  The value of String str1 is '{str1}'.
*  The value of StringBuilder sb is '{sb}'.

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

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

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

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

' Sample for String.Equals(Object)
'            String.Equals(String)
'            String.Equals(String, String)
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
End Class
'
'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
'

Commenti

Questo metodo esegue un confronto ordinale (con distinzione tra maiuscole e minuscole e senza distinzione tra impostazioni cultura).

Vedi anche

CompareOrdinal(String, String)

Si applica a

Equals(String, StringComparison)

Source:: String.Comparison.cs

Source:: String.Comparison.cs

Source:: String.Comparison.cs

Determina se questa stringa e un oggetto String specificato hanno lo stesso valore. Un parametro specifica le impostazioni cultura, l'eventuale distinzione fra maiuscole e minuscole e le regole di ordinamento usate per effettuare il confronto.

public:
 bool Equals(System::String ^ value, StringComparison comparisonType);

public bool Equals (string value, StringComparison comparisonType);

public bool Equals (string? value, StringComparison comparisonType);

override this.Equals : string * StringComparison -> bool

Public Function Equals (value As String, comparisonType As StringComparison) As Boolean

Parametri

value: String

Stringa da confrontare con questa istanza.

comparisonType: StringComparison

Uno dei valori di enumerazione che specifica la modalità di confronto delle stringhe.

Restituisce

Boolean

true se il valore del parametro value corrisponde a quello di questa stringa; in caso contrario, false.

Eccezioni

ArgumentException

comparisonType non è un valore di StringComparison.

Esempio

Nell'esempio seguente viene creata una matrice di stringhe costituita da una "I" maiuscola, una minuscola "i" e una "ı" senza punti. Chiama quindi il Equals(String, StringComparison) metodo per confrontarli usando ogni valore di enumerazione possibile StringComparison .

using System;

class Sample 
{
   public static void Main() 
   {
      // Define a string array with the following three "I" characters:
      //      U+0069, U+0131, and U+0049.  
      string[] threeIs = { "i", "ı", "I" };
      // Define Type object representing StringComparison type.
      Type scType = typeof(StringComparison);  
      
      // Show the current culture (for culture-sensitive string comparisons).
      Console.WriteLine("The current culture is {0}.\n", 
                        System.Globalization.CultureInfo.CurrentCulture.Name);
        
      // Perform comparisons using each StringComparison member. 
      foreach (string scName in Enum.GetNames(scType))
      {
         StringComparison sc = (StringComparison) Enum.Parse(scType, scName);
         Console.WriteLine("Comparisons using {0}:", sc);
         // Compare each character in character array.
         for (int ctr = 0; ctr <= 1; ctr++)
         {
            string instanceChar = threeIs[ctr];
            for (int innerCtr = ctr + 1; innerCtr <= threeIs.GetUpperBound(0); innerCtr++)
            {
               string otherChar = threeIs[innerCtr];
               Console.WriteLine("{0} (U+{1}) = {2} (U+{3}): {4}", 
                                 instanceChar, Convert.ToInt16(Char.Parse(instanceChar)).ToString("X4"), 
                                 otherChar, Convert.ToInt16(Char.Parse(otherChar)).ToString("X4"), 
                                 instanceChar.Equals(otherChar, sc));
            }
            Console.WriteLine();
         }
      }   
   }
}
// The example displays the following output:
//       The current culture is en-US.
//       
//       Comparisons using CurrentCulture:
//       i (U+0069) = ı (U+0131): False
//       i (U+0069) = I (U+0049): False
//       
//       ı (U+0131) = I (U+0049): False
//       
//       Comparisons using CurrentCultureIgnoreCase:
//       i (U+0069) = ı (U+0131): False
//       i (U+0069) = I (U+0049): True
//       
//       ı (U+0131) = I (U+0049): False
//       
//       Comparisons using InvariantCulture:
//       i (U+0069) = ı (U+0131): False
//       i (U+0069) = I (U+0049): False
//       
//       ı (U+0131) = I (U+0049): False
//       
//       Comparisons using InvariantCultureIgnoreCase:
//       i (U+0069) = ı (U+0131): False
//       i (U+0069) = I (U+0049): True
//       
//       ı (U+0131) = I (U+0049): False
//       
//       Comparisons using Ordinal:
//       i (U+0069) = ı (U+0131): False
//       i (U+0069) = I (U+0049): False
//       
//       ı (U+0131) = I (U+0049): False
//       
//       Comparisons using OrdinalIgnoreCase:
//       i (U+0069) = ı (U+0131): False
//       i (U+0069) = I (U+0049): True
//       
//       ı (U+0131) = I (U+0049): False

open System
open System.Globalization

// Define a string array with the following three "I" characters:
//      U+0069, U+0131, and U+0049.  
let threeIs = [| "i"; "ı"; "I" |]
// Define Type object representing StringComparison type.
let scType = typeof<StringComparison>  

// Show the current culture (for culture-sensitive string comparisons).
printfn $"The current culture is {CultureInfo.CurrentCulture.Name}.\n"

// Perform comparisons using each StringComparison member. 
for scName in Enum.GetNames scType do
    let sc = Enum.Parse(scType, scName) :?> StringComparison
    printfn $"Comparisons using {sc}:"
    // Compare each character in character array.
    for ctr = 0 to 1 do
        let instanceChar = threeIs[ctr]
        for innerCtr = ctr + 1 to threeIs.GetUpperBound 0 do
            let otherChar = threeIs[innerCtr]
            printfn $"{instanceChar} (U+{Convert.ToInt16(Char.Parse instanceChar):X4}) = {otherChar} (U+{Convert.ToInt16(Char.Parse otherChar):X4}): {instanceChar.Equals(otherChar, sc)}"
        printfn ""
// The example displays the following output:
//       The current culture is en-US.
//       
//       Comparisons using CurrentCulture:
//       i (U+0069) = i (U+0131): False
//       i (U+0069) = I (U+0049): False
//       
//       i (U+0131) = I (U+0049): False
//       
//       Comparisons using CurrentCultureIgnoreCase:
//       i (U+0069) = i (U+0131): False
//       i (U+0069) = I (U+0049): True
//       
//       i (U+0131) = I (U+0049): False
//       
//       Comparisons using InvariantCulture:
//       i (U+0069) = i (U+0131): False
//       i (U+0069) = I (U+0049): False
//       
//       i (U+0131) = I (U+0049): False
//       
//       Comparisons using InvariantCultureIgnoreCase:
//       i (U+0069) = i (U+0131): False
//       i (U+0069) = I (U+0049): True
//       
//       i (U+0131) = I (U+0049): False
//       
//       Comparisons using Ordinal:
//       i (U+0069) = i (U+0131): False
//       i (U+0069) = I (U+0049): False
//       
//       i (U+0131) = I (U+0049): False
//       
//       Comparisons using OrdinalIgnoreCase:
//       i (U+0069) = i (U+0131): False
//       i (U+0069) = I (U+0049): True
//       
//       i (U+0131) = I (U+0049): False

Class Sample
   Public Shared Sub Main() 
      ' Define a string array with the following three "I" characters:
      '      U+0069, U+0131, and U+0049.  
      Dim threeIs() As String = { "i", "ı", "I" }
      ' Define Type object representing StringComparison type.
      Dim scType As Type = GetType(StringComparison)  
      
      ' Show the current culture (for culture-sensitive string comparisons).
      Console.WriteLine("The current culture is {0}." & vbCrLf, _
                        System.Globalization.CultureInfo.CurrentCulture.Name)
        
      ' Perform comparisons using each StringComparison member. 
      For Each scName As String In [Enum].GetNames(scType)
         Dim sc As StringComparison = [Enum].Parse(scType, scName)
         Console.WriteLine("Comparisons using {0}:", sc)
         ' Compare each character in character array.
         For ctr As Integer = 0 To 1
            Dim instanceChar As String = threeIs(ctr)
            For innerCtr As Integer = ctr + 1 To threeIs.GetUpperBound(0)
               Dim otherChar As STring = threeIs(innerCtr)
               Console.WriteLine("{0} (U+{1}) = {2} (U+{3}): {4}", _
                                 instanceChar, Convert.ToInt16(Char.Parse(instanceChar)).ToString("X4"), _
                                 otherChar, Convert.ToInt16(Char.Parse(otherChar)).ToString("X4"), _
                                 instanceChar.Equals(otherChar, sc))
            Next
            Console.WriteLine()
         Next
      Next              
   End Sub
End Class
' The example displays the following output:
'       The current culture is en-US.
'       
'       Comparisons using CurrentCulture:
'       i (U+0069) = i (U+0131): False
'       i (U+0069) = I (U+0049): False
'       
'       i (U+0131) = I (U+0049): False
'       
'       Comparisons using CurrentCultureIgnoreCase:
'       i (U+0069) = i (U+0131): False
'       i (U+0069) = I (U+0049): True
'       
'       i (U+0131) = I (U+0049): False
'       
'       Comparisons using InvariantCulture:
'       i (U+0069) = i (U+0131): False
'       i (U+0069) = I (U+0049): False
'       
'       i (U+0131) = I (U+0049): False
'       
'       Comparisons using InvariantCultureIgnoreCase:
'       i (U+0069) = i (U+0131): False
'       i (U+0069) = I (U+0049): True
'       
'       i (U+0131) = I (U+0049): False
'       
'       Comparisons using Ordinal:
'       i (U+0069) = i (U+0131): False
'       i (U+0069) = I (U+0049): False
'       
'       i (U+0131) = I (U+0049): False
'       
'       Comparisons using OrdinalIgnoreCase:
'       i (U+0069) = i (U+0131): False
'       i (U+0069) = I (U+0049): True
'       
'       i (U+0131) = I (U+0049): False

Commenti

Il comparisonType parametro indica se il confronto deve usare le impostazioni cultura correnti o invarianti, rispettare o ignorare il caso delle due stringhe confrontate oppure usare le regole di ordinamento ordinale o word.

Vedi anche

CompareOrdinal(String, String)

Si applica a

Equals(String, String, StringComparison)

Source:: String.Comparison.cs

Source:: String.Comparison.cs

Source:: String.Comparison.cs

Determina se due oggetti String specificati hanno lo stesso valore. Un parametro specifica le impostazioni cultura, l'eventuale distinzione fra maiuscole e minuscole e le regole di ordinamento usate per effettuare il confronto.

public:
 static bool Equals(System::String ^ a, System::String ^ b, StringComparison comparisonType);

public static bool Equals (string a, string b, StringComparison comparisonType);

public static bool Equals (string? a, string? b, StringComparison comparisonType);

static member Equals : string * string * StringComparison -> bool

Public Shared Function Equals (a As String, b As String, comparisonType As StringComparison) As Boolean

Parametri

a: String

Prima stringa da confrontare o null.

b: String

Seconda stringa da confrontare o null.

comparisonType: StringComparison

Uno dei valori di enumerazione che specifica le regole di confronto.

Restituisce

Boolean

true se il valore del parametro a è uguale al valore del parametro b; in caso contrario, false.

Eccezioni

ArgumentException

comparisonType non è un valore di StringComparison.

Esempio

Nell'esempio seguente vengono confrontati tre set di stringhe usando ogni membro dell'enumerazione StringComparison . I confronti usano le convenzioni delle impostazioni cultura inglese (Stati Uniti), Thai (Thailandia) e Turco (Turchia). Si noti che le stringhe "a" e "a-" sono considerate equivalenti nelle impostazioni cultura "th-TH", ma non nelle altre, mentre "i" e "İ" sono considerate equivalenti nelle impostazioni cultura "tr-TR" quando il caso viene ignorato ma non nelle altre impostazioni cultura.

using System;
using System.Globalization;
using System.Threading;

public class Example3
{
    public static void Main()
    {
        String[] cultureNames = { "en-US", "th-TH", "tr-TR" };
        String[] strings1 = { "a", "i", "case", };
        String[] strings2 = { "a-", "\u0130", "Case" };
        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
//       a = a- (CurrentCulture): False
//       a = a- (CurrentCultureIgnoreCase): False
//       a = a- (InvariantCulture): False
//       a = a- (InvariantCultureIgnoreCase): False
//       a = a- (Ordinal): False
//       a = a- (OrdinalIgnoreCase): False
//
//       i = İ (CurrentCulture): False
//       i = İ (CurrentCultureIgnoreCase): False
//       i = İ (InvariantCulture): False
//       i = İ (InvariantCultureIgnoreCase): False
//       i = İ (Ordinal): False
//       i = İ (OrdinalIgnoreCase): False
//
//       case = Case (CurrentCulture): False
//       case = Case (CurrentCultureIgnoreCase): True
//       case = Case (InvariantCulture): False
//       case = Case (InvariantCultureIgnoreCase): True
//       case = Case (Ordinal): False
//       case = Case (OrdinalIgnoreCase): True
//
//
//    Current Culture: th-TH
//       a = a- (CurrentCulture): True
//       a = a- (CurrentCultureIgnoreCase): True
//       a = a- (InvariantCulture): False
//       a = a- (InvariantCultureIgnoreCase): False
//       a = a- (Ordinal): False
//       a = a- (OrdinalIgnoreCase): False
//
//       i = İ (CurrentCulture): False
//       i = İ (CurrentCultureIgnoreCase): False
//       i = İ (InvariantCulture): False
//       i = İ (InvariantCultureIgnoreCase): False
//       i = İ (Ordinal): False
//       i = İ (OrdinalIgnoreCase): False
//
//       case = Case (CurrentCulture): False
//       case = Case (CurrentCultureIgnoreCase): True
//       case = Case (InvariantCulture): False
//       case = Case (InvariantCultureIgnoreCase): True
//       case = Case (Ordinal): False
//       case = Case (OrdinalIgnoreCase): True
//
//
//    Current Culture: tr-TR
//       a = a- (CurrentCulture): False
//       a = a- (CurrentCultureIgnoreCase): False
//       a = a- (InvariantCulture): False
//       a = a- (InvariantCultureIgnoreCase): False
//       a = a- (Ordinal): False
//       a = a- (OrdinalIgnoreCase): False
//
//       i = İ (CurrentCulture): False
//       i = İ (CurrentCultureIgnoreCase): True
//       i = İ (InvariantCulture): False
//       i = İ (InvariantCultureIgnoreCase): False
//       i = İ (Ordinal): False
//       i = İ (OrdinalIgnoreCase): False
//
//       case = Case (CurrentCulture): False
//       case = Case (CurrentCultureIgnoreCase): True
//       case = Case (InvariantCulture): False
//       case = Case (InvariantCultureIgnoreCase): True
//       case = Case (Ordinal): False
//       case = Case (OrdinalIgnoreCase): True

open System
open System.Globalization
open System.Threading

let cultureNames = 
    [| "en-US"; "se-SE" |]
let strings1 = 
    [| "case"; "encyclopædia" 
       "encyclopædia"; "Archæology" |]
let strings2 = 
    [| "Case"; "encyclopaedia" 
       "encyclopedia"; "ARCHÆOLOGY" |]
let comparisons = 
    Enum.GetValues typeof<StringComparison> :?> StringComparison[]

for cultureName in cultureNames do
    Thread.CurrentThread.CurrentCulture <- CultureInfo.CreateSpecificCulture cultureName
    printfn $"Current Culture: {CultureInfo.CurrentCulture.Name}"
    for i = 0 to strings1.GetUpperBound 0 do
        for comparison in comparisons do
            printfn $"   {strings1[i]} = {strings2[i]} ({comparison}): {String.Equals(strings1[i], strings2[i], comparison)}"
        printfn ""         
    printfn ""
// 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

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

Commenti

Vedi anche

CompareOrdinal(String, String)

Si applica a

String.Equals Metodo

Definizione

Overload

Equals(Object)

Parametri

Restituisce

Esempio

Commenti

Vedi anche

Si applica a

Equals(String)

Parametri

Restituisce

Implementazioni

Esempio

Commenti

Vedi anche

Si applica a

Equals(String, String)

Parametri

Restituisce

Esempio

Commenti

Vedi anche

Si applica a

Equals(String, StringComparison)

Parametri

Restituisce

Eccezioni

Esempio

Commenti

Vedi anche

Si applica a

Equals(String, String, StringComparison)

Parametri

Restituisce

Eccezioni

Esempio

Commenti

Vedi anche

Si applica a

Commenti e suggerimenti

Risorse aggiuntive