String.CompareTo Metodo

  • Riferimento

Definizione

Spazio dei nomi:
System
Assembly:
System.Runtime.dll
Assembly:
mscorlib.dll
Assembly:
netstandard.dll

Confronta questa istanza con String o un oggetto specificato e restituisce un intero che indica se questa istanza precede, segue o si trova nella stessa posizione di String o dell'oggetto specificato nell'ordinamento.

Overload

CompareTo(Object)

Confronta questa istanza con un oggetto Object specificato e indica se questa istanza precede, segue o si trova nella stessa posizione dell'oggetto Object specificato all'interno dell'ordinamento.
CompareTo(String)

Confronta questa istanza con un oggetto String specificato e indica se questa istanza precede, segue o si trova nella stessa posizione della stringa specificata all'interno dei criteri di ordinamento.

Commenti

Entrambi gli overload del metodo eseguono un CompareTo confronto con distinzione tra maiuscole e minuscole e con distinzione tra maiuscole e minuscole. Non è possibile utilizzare questo metodo per eseguire confronti con impostazioni cultura senza distinzione tra impostazioni cultura o ordinali. Per maggiore chiarezza, è consigliabile evitare il CompareTo metodo e chiamare invece il Compare metodo .

CompareTo(Object)

Origine:
String.Comparison.cs
Origine:
String.Comparison.cs
Origine:
String.Comparison.cs

Confronta questa istanza con un oggetto Object specificato e indica se questa istanza precede, segue o si trova nella stessa posizione dell'oggetto Object specificato all'interno dell'ordinamento.

public:
 virtual int CompareTo(System::Object ^ value);
public int CompareTo (object? value);
public int CompareTo (object value);
abstract member CompareTo : obj -> int
override this.CompareTo : obj -> int
Public Function CompareTo (value As Object) As Integer

Parametri

value
Object

Oggetto che restituisce un oggetto String.

Restituisce

Int32

Intero con segno a 32 bit che indica se questa istanza precede, segue o si trova nella stessa posizione del parametro value nell'ordinamento.

Valore Condizione
Minore di zero Questa istanza precede value.
Zero Questa istanza si trova nella stessa posizione di value nell'ordinamento.
Maggiore di zero L'istanza segue value.

-oppure-

value è null.

Implementazioni

CompareTo(Object)

Eccezioni

ArgumentException

value non è un oggetto String.

Esempio

Nell'esempio seguente viene utilizzato il CompareTo metodo con un oggetto Object. Poiché tenta di confrontare un'istanza String con un TestClass oggetto , il metodo genera un'eccezione ArgumentException.

using namespace System;

public ref class TestClass{};

int main()
{
   TestClass^ test = gcnew TestClass;
   array<Object^>^ objectsToCompare = { test, test->ToString(), 123,
                                        (123).ToString(), "some text",
                                        "Some Text" };
   String^ s = "some text";
   for each (Object^ objectToCompare in objectsToCompare) {
      try {
         Int32 i = s->CompareTo(objectToCompare);
         Console::WriteLine("Comparing '{0}' with '{1}': {2}",
                            s, objectToCompare, i);
      }
      catch (ArgumentException^ e) {
         Console::WriteLine("Bad argument: {0} (type {1})",
                            objectToCompare,
                            objectToCompare->GetType()->Name);
      }
   }
}
// The example displays the following output:
//    Bad argument: TestClass (type TestClass)
//    Comparing 'some text' with 'TestClass': -1
//    Bad argument: 123 (type Int32)
//    Comparing 'some text' with '123': 1
//    Comparing 'some text' with 'some text': 0
//    Comparing 'some text' with 'Some Text': -1

using System;

public class TestClass
{}

public class Example
{
   public static void Main()
   {
      var test = new TestClass();
      Object[] objectsToCompare = { test, test.ToString(), 123,
                                    123.ToString(), "some text",
                                    "Some Text" };
      string s = "some text";
      foreach (var objectToCompare in objectsToCompare) {
         try {
            int i = s.CompareTo(objectToCompare);
            Console.WriteLine("Comparing '{0}' with '{1}': {2}",
                              s, objectToCompare, i);
         }
         catch (ArgumentException) {
            Console.WriteLine("Bad argument: {0} (type {1})",
                              objectToCompare,
                              objectToCompare.GetType().Name);
         }
      }
   }
}
// The example displays the following output:
//    Bad argument: TestClass (type TestClass)
//    Comparing 'some text' with 'TestClass': -1
//    Bad argument: 123 (type Int32)
//    Comparing 'some text' with '123': 1
//    Comparing 'some text' with 'some text': 0
//    Comparing 'some text' with 'Some Text': -1

open System

type TestClass() = class end

let test = TestClass()
let objectsToCompare: obj list =
    [ test; string test; 123
      string 123; "some text"
      "Some Text" ]
let s = "some text"
for objectToCompare in objectsToCompare do
    try
        let i = s.CompareTo objectToCompare
        printfn $"Comparing '{s}' with '{objectToCompare}': {i}"
    with :? ArgumentException ->
        printfn $"Bad argument: {objectToCompare} (type {objectToCompare.GetType().Name})"
// The example displays the following output:
//    Bad argument: TestClass (type TestClass)
//    Comparing 'some text' with 'TestClass': -1
//    Bad argument: 123 (type Int32)
//    Comparing 'some text' with '123': 1
//    Comparing 'some text' with 'some text': 0
//    Comparing 'some text' with 'Some Text': -1

Public Class TestClass
End Class 


Public Class Example
   Public Shared Sub Main()
      Dim test As New TestClass()
      Dim objectsToCompare() As Object = { test, test.ToString(), 123,
                                           123.ToString(), "some text",
                                           "Some Text" }
      Dim s As String = "some text"
      For Each objectToCompare In objectsToCompare
         Try
            Dim i As Integer = s.CompareTo(objectToCompare)
            Console.WriteLine("Comparing '{0}' with '{1}': {2}",
                              s, objectToCompare, i)
         Catch e As ArgumentException
            Console.WriteLine("Bad argument: {0} (type {1})",
                              objectToCompare,
                              objectToCompare.GetType().Name)
         End Try
      Next
   End Sub 
End Class 
' The example displays the following output:
'       Bad argument: TestClass (type TestClass)
'       Comparing 'some text' with 'TestClass': -1
'       Bad argument: 123 (type Int32)
'       Comparing 'some text' with '123': 1
'       Comparing 'some text' with 'some text': 0
'       Comparing 'some text' with 'Some Text': -1

Commenti

value deve essere un String oggetto .

Attenzione

Il CompareTo metodo è stato progettato principalmente per l'uso nelle operazioni di ordinamento o di alfabetizzazione. Non deve essere usato quando lo scopo principale della chiamata al metodo consiste nel determinare se due stringhe sono equivalenti. Per determinare se due stringhe sono equivalenti, chiamare il Equals metodo .

Questo metodo esegue un confronto di parole (con distinzione tra maiuscole e minuscole e con distinzione tra impostazioni cultura) usando le impostazioni cultura correnti. Per altre informazioni sugli ordinali di parole, stringhe e ordinali, vedere System.Globalization.CompareOptions.

Per altre informazioni sul comportamento di questo metodo, vedere la sezione Osservazioni del String.Compare(String, String) metodo .

Note per i chiamanti

I set di caratteri includono caratteri ignorabili. Il CompareTo(Object) metodo non considera tali caratteri quando esegue un confronto con distinzione tra impostazioni cultura. Ad esempio, se il codice seguente viene eseguito in .NET Framework 4 o versione successiva, un confronto tra "animale" e "ani-mal" (usando un trattino morbido o U+00AD) indica che le due stringhe sono equivalenti.

using System;

public class Example
{
   public static void Main()
   {
      string s1 = "ani\u00ADmal";
      object o1 = "animal";
      
      Console.WriteLine("Comparison of '{0}' and '{1}': {2}", 
                        s1, o1, s1.CompareTo(o1));
   }
}
// The example displays the following output:
//       Comparison of 'ani-mal' and 'animal': 0

let s1 = "ani\u00ADmal"
let o1: obj = "animal"
      
printfn $"Comparison of '{s1}' and '{o1}': {s1.CompareTo o1}"
// The example displays the following output:
//       Comparison of 'ani-mal' and 'animal': 0

Module Example
   Public Sub Main()
      Dim s1 As String = "ani" + ChrW(&h00AD) + "mal"
      Dim o1 As Object = "animal"
      
      Console.WriteLine("Comparison of '{0}' and '{1}': {2}", 
                        s1, o1, s1.CompareTo(o1))
  End Sub
End Module
' The example displays the following output:
'       Comparison of 'ani-mal' and 'animal': 0

Per riconoscere i caratteri ignorabili in un confronto tra stringhe, chiamare il CompareOrdinal(String, String) metodo .

Vedi anche

Si applica a

CompareTo(String)

Origine:
String.Comparison.cs
Origine:
String.Comparison.cs
Origine:
String.Comparison.cs

Confronta questa istanza con un oggetto String specificato e indica se questa istanza precede, segue o si trova nella stessa posizione della stringa specificata all'interno dei criteri di ordinamento.

public:
 virtual int CompareTo(System::String ^ strB);
public:
 int CompareTo(System::String ^ strB);
public int CompareTo (string strB);
public int CompareTo (string? strB);
abstract member CompareTo : string -> int
override this.CompareTo : string -> int
member this.CompareTo : string -> int
Public Function CompareTo (strB As String) As Integer

Parametri

strB
String

Stringa da confrontare con questa istanza.

Restituisce

Int32

Intero con segno a 32 bit che indica se questa istanza precede, segue o si trova nella stessa posizione del parametro strB nell'ordinamento.

Valore Condizione
Minore di zero Questa istanza precede strB.
Zero Questa istanza si trova nella stessa posizione di strB nell'ordinamento.
Maggiore di zero L'istanza segue strB.

-oppure-

strB è null.

Implementazioni

CompareTo(T)

Esempio

Nell'esempio seguente viene utilizzato il CompareTo metodo per confrontare l'istanza di stringa corrente con un'altra stringa.

using namespace System;

String^ CompareStrings(String^ str1, String^ str2)
{
   // compare the values, using the CompareTo method on the first string
   int cmpVal = str1->CompareTo(str2);
   if (cmpVal == 0)
      // the values are the same
      return "The strings occur in the same position in the sort order.";
   else if (cmpVal < 0)
      return "The first string precedes the second in the sort order.";
   else
      return "The first string follows the second in the sort order.";
}

int main()
{
   String^ strFirst = "Goodbye";
   String^ strSecond = "Hello";
   String^ strThird = "a small String*";
   String^ strFourth = "goodbye";
   
   // Compare a string to itself.
   Console::WriteLine(CompareStrings(strFirst, strFirst));
   Console::WriteLine(CompareStrings(strFirst, strSecond));
   Console::WriteLine(CompareStrings(strFirst, strThird));
   
   // Compare a string to another string that varies only by case.
   Console::WriteLine(CompareStrings(strFirst, strFourth));
   Console::WriteLine(CompareStrings(strFourth, strFirst));
}
// The example displays the following output:
//       The strings occur in the same position in the sort order.
//       The first string precedes the second in the sort order.
//       The first string follows the second in the sort order.
//       The first string follows the second in the sort order.
//       The first string precedes the second in the sort order.

using System;

public class Example
{
   public static void Main()
   {
      string strFirst = "Goodbye";
      string strSecond = "Hello";
      string strThird = "a small string";
      string strFourth = "goodbye";

      // Compare a string to itself.
      Console.WriteLine(CompareStrings(strFirst, strFirst));

      Console.WriteLine(CompareStrings(strFirst, strSecond));
      Console.WriteLine(CompareStrings(strFirst, strThird));

      // Compare a string to another string that varies only by case.
      Console.WriteLine(CompareStrings(strFirst, strFourth));
      Console.WriteLine(CompareStrings(strFourth, strFirst));
   }

   private static string CompareStrings( string str1, string str2 )
   {
      // Compare the values, using the CompareTo method on the first string.
      int cmpVal = str1.CompareTo(str2);

       if (cmpVal == 0) // The strings are the same.
         return "The strings occur in the same position in the sort order.";
      else if (cmpVal < 0)
         return "The first string precedes the second in the sort order.";
      else
         return "The first string follows the second in the sort order.";
    }
}
// The example displays the following output:
//       The strings occur in the same position in the sort order.
//       The first string precedes the second in the sort order.
//       The first string follows the second in the sort order.
//       The first string follows the second in the sort order.
//       The first string precedes the second in the sort order.

let strFirst = "Goodbye"
let strSecond = "Hello"
let strThird = "a small string"
let strFourth = "goodbye"

let compareStrings (str1: string) str2 =
    // Compare the values, using the CompareTo method on the first string.
    match str1.CompareTo str2 with
    | 0 -> // The strings are the same.
        "The strings occur in the same position in the sort order."
    | x when x < 0 ->
        "The first string precedes the second in the sort order."
    | _ ->
        "The first string follows the second in the sort order."

// Compare a string to itself.
printfn $"{compareStrings strFirst strFirst}"

printfn $"{compareStrings strFirst strSecond}"
printfn $"{compareStrings strFirst strThird}"

// Compare a string to another string that varies only by case.
printfn $"{compareStrings strFirst strFourth}"
printfn $"{compareStrings strFourth strFirst}"

// The example displays the following output:
//       The strings occur in the same position in the sort order.
//       The first string precedes the second in the sort order.
//       The first string follows the second in the sort order.
//       The first string follows the second in the sort order.
//       The first string precedes the second in the sort order.

Public Module Example
   Public Sub Main()
      Dim strFirst As String = "Goodbye"
      Dim strSecond As String = "Hello"
      Dim strThird As String = "a small string"
      Dim strFourth As String = "goodbye"

      ' Compare a string to itself.
      Console.WriteLine(CompareStrings(strFirst, strFirst))
        
      Console.WriteLine(CompareStrings(strFirst, strSecond))
      Console.WriteLine(CompareStrings(strFirst, strThird))
        
      ' Compare a string to another string that varies only by case.
      Console.WriteLine(CompareStrings(strFirst, strFourth))
      Console.WriteLine(CompareStrings(strFourth, strFirst))
   End Sub
    
   Private Function CompareStrings(str1 As String, str2 As String) As String
      Dim cmpVal As Integer = str1.CompareTo(str2)
      If cmpVal = 0 Then
         ' The values are the same.
         Return "The strings occur in the same position in the sort order."
      ElseIf cmpVal < 0 Then
         Return "The first string precedes the second in the sort order."
      Else
         Return "The first string follows the second in the sort order."
      End If
   End Function
End Module
' This example displays the following output:
'       The strings occur in the same position in the sort order.
'       The strings occur in the same position in the sort order.
'       The first string precedes the second in the sort order.
'       The first string follows the second in the sort order.
'       The first string follows the second in the sort order.
'       The first string precedes the second in the sort order.

Nell'esempio seguente vengono illustrate versioni generiche e non generiche del metodo CompareTo per diversi tipi di valore e riferimento.

// This example demonstrates the two versions of the 
// CompareTo method for several base types.
// The general version takes a parameter of type Object, while the specific
// version takes a type-specific parameter, such as Boolean, Int32, or Double.
using namespace System;

void Show( String^ caption, Object^ var1, Object^ var2, int resultGeneric, int resultNonGeneric )
{
   String^ relation;
   Console::Write( caption );
   if ( resultGeneric == resultNonGeneric )
   {
      if ( resultGeneric < 0 )
            relation = "less than";
      else
      if ( resultGeneric > 0 )
            relation = "greater than";
      else
            relation = "equal to";
      Console::WriteLine( "{0} is {1} {2}", var1, relation, var2 );
   }
   // The following condition will never occur because the generic and non-generic
   // CompareTo methods are equivalent.
   else
   {
      Console::WriteLine( "Generic CompareTo = {0}; non-generic CompareTo = {1}", resultGeneric, resultNonGeneric );
   }
}

int main()
{
   String^ nl = Environment::NewLine;
   String^ msg = "{0}The following is the result of using the generic and non-generic{0}"
   "versions of the CompareTo method for several base types:{0}";
   Object^ obj; // An Object used to insure CompareTo(Object) is called.

   DateTime now = DateTime::Now;
   
   // Time span = 11 days, 22 hours, 33 minutes, 44 seconds
   TimeSpan tsX = TimeSpan(11,22,33,44);
   
   // Version = 1.2.333.4
   Version^ versX = gcnew Version(  "1.2.333.4" );
   
   // Guid = CA761232-ED42-11CE-BACD-00AA0057B223
   Guid guidX = Guid( "{CA761232-ED42-11CE-BACD-00AA0057B223}");
   Boolean a1 = true,a2 = true;
   Byte b1 = 1,b2 = 1;
   Int16 c1 = -2,c2 = 2;
   Int32 d1 = 3,d2 = 3;
   Int64 e1 = 4,e2 = -4;
   Decimal f1 = Decimal(-5.5), f2 = Decimal(5.5);
   Single g1 = 6.6f,g2 = 6.6f;
   Double h1 = 7.7,h2 = -7.7;
   Char i1 = 'A',i2 = 'A';
   String^ j1 = "abc", ^j2 = "abc";
   DateTime k1 = now,k2 = now;
   TimeSpan l1 = tsX,l2 = tsX;
   Version^ m1 = versX, ^m2 = gcnew Version(  "2.0" );
   Guid n1 = guidX,n2 = guidX;
   
   // The following types are not CLS-compliant.
   SByte w1 = 8,w2 = 8;
   UInt16 x1 = 9,x2 = 9;
   UInt32 y1 = 10,y2 = 10;
   UInt64 z1 = 11,z2 = 11;
   
   //
   Console::WriteLine( msg, nl );
   try
   {
      Show( "Boolean: ", a1, a2, a1.CompareTo( a2 ), a1.CompareTo( a2 ) );
      Show( "Byte:    ", b1, b2, b1.CompareTo( b2 ), b1.CompareTo( b2 ) );
      Show( "Int16:   ", c1, c2, c1.CompareTo( c2 ), c1.CompareTo( c2 ) );
      Show( "Int32:   ", d1, d2, d1.CompareTo( d2 ), d1.CompareTo( d2 ) );
      Show( "Int64:   ", e1, e2, e1.CompareTo( e2 ), e1.CompareTo( e2 ) );
      Show( "Decimal: ", f1, f2, f1.CompareTo( f2 ), f1.CompareTo( f2 ) );
      Show( "Single:  ", g1, g2, g1.CompareTo( g2 ), g1.CompareTo( g2 ) );
      Show( "Double:  ", h1, h2, h1.CompareTo( h2 ), h1.CompareTo( h2 ) );
      Show( "Char:    ", i1, i2, i1.CompareTo( i2 ), i1.CompareTo( i2 ) );
      
      // Use an anonymous object to hide the String object.
      obj = j2;
      Show( "String:  ", j1, j2, j1->CompareTo( j2 ), j1->CompareTo( obj ) );
      Show( "DateTime:", k1, k2, k1.CompareTo( k2 ), k1.CompareTo( k2 ) );
      Show(  "TimeSpan: ", l1, l2, l1.CompareTo( l2 ), l1.CompareTo( l2 ) );
      
      // Use an anonymous object to hide the Version object.
      obj = m2;
      Show(  "Version:  ", m1, m2, m1->CompareTo( m2 ), m1->CompareTo( obj ) );
      Show(  "Guid:     ", n1, n2, n1.CompareTo( n2 ), n1.CompareTo( n2 ) );
      
      //
      Console::WriteLine( "{0}The following types are not CLS-compliant:", nl );
      Show( "SByte:   ", w1, w2, w1.CompareTo( w2 ), w1.CompareTo( w2 ) );
      Show( "UInt16:  ", x1, x2, x1.CompareTo( x2 ), x1.CompareTo( x2 ) );
      Show( "UInt32:  ", y1, y2, y1.CompareTo( y2 ), y1.CompareTo( y2 ) );
      Show( "UInt64:  ", z1, z2, z1.CompareTo( z2 ), z1.CompareTo( z2 ) );
   }
   catch ( Exception^ e ) 
   {
      Console::WriteLine( e );
   }

}
//     This example displays the following output:
//     
//     The following is the result of using the generic and non-generic versions of the
//     CompareTo method for several base types:
//     
//     Boolean:  True is equal to True
//     Byte:     1 is equal to 1
//     Int16:    -2 is less than 2
//     Int32:    3 is equal to 3
//     Int64:    4 is greater than -4
//     Decimal:  -5.5 is less than 5.5
//     Single:   6.6 is equal to 6.6
//     Double:   7.7 is greater than -7.7
//     Char:     A is equal to A
//     String:   abc is equal to abc
//     DateTime: 12/1/2003 5:37:46 PM is equal to 12/1/2003 5:37:46 PM
//     TimeSpan: 11.22:33:44 is equal to 11.22:33:44
//     Version:  1.2.333.4 is less than 2.0
//     Guid:     ca761232-ed42-11ce-bacd-00aa0057b223 is equal to ca761232-ed42-11ce-bacd-00
//     aa0057b223
//     
//     The following types are not CLS-compliant:
//     SByte:    8 is equal to 8
//     UInt16:   9 is equal to 9
//     UInt32:   10 is equal to 10
//     UInt64:   11 is equal to 11

// This example demonstrates the generic and non-generic versions of the
// CompareTo method for several base types.
// The non-generic version takes a parameter of type Object, while the generic
// version takes a type-specific parameter, such as Boolean, Int32, or Double.

using System;

class Sample
{
    public static void Main()
    {
    string    nl = Environment.NewLine;
    string    msg = "{0}The following is the result of using the generic and non-generic{0}" +
                    "versions of the CompareTo method for several base types:{0}";

    DateTime  now = DateTime.Now;
// Time span = 11 days, 22 hours, 33 minutes, 44 seconds
    TimeSpan  tsX = new TimeSpan(11, 22, 33, 44);
// Version = 1.2.333.4
    Version   versX = new Version("1.2.333.4");
// Guid = CA761232-ED42-11CE-BACD-00AA0057B223
    Guid      guidX = new Guid("{CA761232-ED42-11CE-BACD-00AA0057B223}");

    Boolean  a1 = true,  a2 = true;
    Byte     b1 = 1,     b2 = 1;
    Int16    c1 = -2,    c2 = 2;
    Int32    d1 = 3,     d2 = 3;
    Int64    e1 = 4,     e2 = -4;
    Decimal  f1 = -5.5m, f2 = 5.5m;
    Single   g1 = 6.6f,  g2 = 6.6f;
    Double   h1 = 7.7d,  h2 = -7.7d;
    Char     i1 = 'A',   i2 = 'A';
    String   j1 = "abc", j2 = "abc";
    DateTime k1 = now,   k2 = now;
    TimeSpan l1 = tsX,   l2 = tsX;
    Version  m1 = versX, m2 = new Version("2.0");
    Guid     n1 = guidX, n2 = guidX;

// The following types are not CLS-compliant.
    SByte    w1 = 8,     w2 = 8;
    UInt16   x1 = 9,     x2 = 9;
    UInt32   y1 = 10,    y2 = 10;
    UInt64   z1 = 11,    z2 = 11;
//
    Console.WriteLine(msg, nl);
    try
        {
// The second and third Show method call parameters are automatically boxed because
// the second and third Show method declaration arguments expect type Object.

        Show("Boolean:  ", a1, a2, a1.CompareTo(a2), a1.CompareTo((Object)a2));
        Show("Byte:     ", b1, b2, b1.CompareTo(b2), b1.CompareTo((Object)b2));
        Show("Int16:    ", c1, c2, c1.CompareTo(c2), c1.CompareTo((Object)c2));
        Show("Int32:    ", d1, d2, d1.CompareTo(d2), d1.CompareTo((Object)d2));
        Show("Int64:    ", e1, e2, e1.CompareTo(e2), e1.CompareTo((Object)e2));
        Show("Decimal:  ", f1, f2, f1.CompareTo(f2), f1.CompareTo((Object)f2));
        Show("Single:   ", g1, g2, g1.CompareTo(g2), g1.CompareTo((Object)g2));
        Show("Double:   ", h1, h2, h1.CompareTo(h2), h1.CompareTo((Object)h2));
        Show("Char:     ", i1, i2, i1.CompareTo(i2), i1.CompareTo((Object)i2));
        Show("String:   ", j1, j2, j1.CompareTo(j2), j1.CompareTo((Object)j2));
        Show("DateTime: ", k1, k2, k1.CompareTo(k2), k1.CompareTo((Object)k2));
        Show("TimeSpan: ", l1, l2, l1.CompareTo(l2), l1.CompareTo((Object)l2));
        Show("Version:  ", m1, m2, m1.CompareTo(m2), m1.CompareTo((Object)m2));
        Show("Guid:     ", n1, n2, n1.CompareTo(n2), n1.CompareTo((Object)n2));
//
        Console.WriteLine("{0}The following types are not CLS-compliant:", nl);
        Show("SByte:    ", w1, w2, w1.CompareTo(w2), w1.CompareTo((Object)w2));
        Show("UInt16:   ", x1, x2, x1.CompareTo(x2), x1.CompareTo((Object)x2));
        Show("UInt32:   ", y1, y2, y1.CompareTo(y2), y1.CompareTo((Object)y2));
        Show("UInt64:   ", z1, z2, z1.CompareTo(z2), z1.CompareTo((Object)z2));
        }
    catch (Exception e)
        {
        Console.WriteLine(e);
        }
    }

    public static void Show(string caption, Object var1, Object var2,
                            int resultGeneric, int resultNonGeneric)
    {
    string relation;

    Console.Write(caption);
    if (resultGeneric == resultNonGeneric)
        {
        if      (resultGeneric < 0) relation = "less than";
        else if (resultGeneric > 0) relation = "greater than";
        else                        relation = "equal to";
        Console.WriteLine("{0} is {1} {2}", var1, relation, var2);
        }

// The following condition will never occur because the generic and non-generic
// CompareTo methods are equivalent.

    else
        {
        Console.WriteLine("Generic CompareTo = {0}; non-generic CompareTo = {1}",
                           resultGeneric, resultNonGeneric);
        }
   }
}
/*
This example produces the following results:

The following is the result of using the generic and non-generic versions of the
CompareTo method for several base types:

Boolean:  True is equal to True
Byte:     1 is equal to 1
Int16:    -2 is less than 2
Int32:    3 is equal to 3
Int64:    4 is greater than -4
Decimal:  -5.5 is less than 5.5
Single:   6.6 is equal to 6.6
Double:   7.7 is greater than -7.7
Char:     A is equal to A
String:   abc is equal to abc
DateTime: 12/1/2003 5:37:46 PM is equal to 12/1/2003 5:37:46 PM
TimeSpan: 11.22:33:44 is equal to 11.22:33:44
Version:  1.2.333.4 is less than 2.0
Guid:     ca761232-ed42-11ce-bacd-00aa0057b223 is equal to ca761232-ed42-11ce-bacd-00
aa0057b223

The following types are not CLS-compliant:
SByte:    8 is equal to 8
UInt16:   9 is equal to 9
UInt32:   10 is equal to 10
UInt64:   11 is equal to 11
*/

// This example demonstrates the generic and non-generic versions of the
// CompareTo method for several base types.
// The non-generic version takes a parameter of type Object, while the generic
// version takes a type-specific parameter, such as Boolean, Int32, or Double.
open System

let show caption (var1: obj) (var2: obj) resultGeneric resultNonGeneric =
    printf "%s" caption
    if resultGeneric = resultNonGeneric then
        let relation =
            if resultGeneric < 0 then "less than"
            elif resultGeneric > 0 then "greater than"
            else "equal to"
        printfn $"{var1} is {relation} {var2}"

    // The following condition will never occur because the generic and non-generic
    // CompareTo methods are equivalent.
    else
        printfn $"Generic CompareTo = {resultGeneric} non-generic CompareTo = {resultNonGeneric}"

let now = DateTime.Now
// Time span = 11 days, 22 hours, 33 minutes, 44 seconds
let tsX = TimeSpan(11, 22, 33, 44)
// Version = 1.2.333.4
let versX = Version "1.2.333.4"
// Guid = CA761232-ED42-11CE-BACD-00AA0057B223
let guidX = Guid "{CA761232-ED42-11CE-BACD-00AA0057B223}"

let a1, a2 = true, true
let b1, b2 = 1uy, 1uy
let c1, c2 = -2s, 2s
let d1, d2 = 3, 3
let e1, e2 = 4L, -4L
let f1, f2 = -5.5m, 5.5m
let g1, g2 = 6.6f, 6.6f
let h1, h2 = 7.7, -7.7
let i1, i2 = 'A', 'A'
let j1, j2 = "abc", "abc"
let k1, k2 = now, now
let l1, l2 = tsX, tsX
let m1, m2 = versX, Version "2.0"
let n1, n2 = guidX, guidX

// The following types are not CLS-compliant.
let w1, w2 = 8y, 8y
let x1, x2 = 9us, 9us
let y1, y2 = 10u, 10u
let z1, z2 = 11uL, 11uL

printfn "\nThe following is the result of using the generic and non-generic\nversions of the CompareTo method for several base types:\n"
try
    // The second and third show function call parameters are automatically boxed because
    // the second and third show function declaration arguments expect type Object.
    show "Boolean:  " a1 a2 (a1.CompareTo a2) (a1.CompareTo (a2 :> obj))

    show "Byte:     " b1 b2 (b1.CompareTo b2) (b1.CompareTo (b2 :> obj))
    show "Int16:    " c1 c2 (c1.CompareTo c2) (c1.CompareTo (c2 :> obj))
    show "Int32:    " d1 d2 (d1.CompareTo d2) (d1.CompareTo (d2 :> obj))
    show "Int64:    " e1 e2 (e1.CompareTo e2) (e1.CompareTo (e2 :> obj))
    show "Decimal:  " f1 f2 (f1.CompareTo f2) (f1.CompareTo (f2 :> obj))
    show "Single:   " g1 g2 (g1.CompareTo g2) (g1.CompareTo (g2 :> obj))
    show "Double:   " h1 h2 (h1.CompareTo h2) (h1.CompareTo (h2 :> obj))
    show "Char:     " i1 i2 (i1.CompareTo i2) (i1.CompareTo (i2 :> obj))
    show "String:   " j1 j2 (j1.CompareTo j2) (j1.CompareTo (j2 :> obj))
    show "DateTime: " k1 k2 (k1.CompareTo k2) (k1.CompareTo (k2 :> obj))
    show "TimeSpan: " l1 l2 (l1.CompareTo l2) (l1.CompareTo (l2 :> obj))
    show "Version:  " m1 m2 (m1.CompareTo m2) (m1.CompareTo (m2 :> obj))
    show "Guid:     " n1 n2 (n1.CompareTo n2) (n1.CompareTo (n2 :> obj))

    printfn "\nThe following types are not CLS-compliant:"
    show "SByte:    " w1 w2 (w1.CompareTo w2) (w1.CompareTo (w2 :> obj))
    show "UInt16:   " x1 x2 (x1.CompareTo x2) (x1.CompareTo (x2 :> obj))
    show "UInt32:   " y1 y2 (y1.CompareTo y2) (y1.CompareTo (y2 :> obj))
    show "UInt64:   " z1 z2 (z1.CompareTo z2) (z1.CompareTo (z2 :> obj))
with e -> printfn $"{e}"


// This example produces the following results:
// The following is the result of using the generic and non-generic versions of the
// CompareTo method for several base types:
// Boolean:  True is equal to True
// Byte:     1 is equal to 1
// Int16:    -2 is less than 2
// Int32:    3 is equal to 3
// Int64:    4 is greater than -4
// Decimal:  -5.5 is less than 5.5
// Single:   6.6 is equal to 6.6
// Double:   7.7 is greater than -7.7
// Char:     A is equal to A
// String:   abc is equal to abc
// DateTime: 12/1/2003 5:37:46 PM is equal to 12/1/2003 5:37:46 PM
// TimeSpan: 11.22:33:44 is equal to 11.22:33:44
// Version:  1.2.333.4 is less than 2.0
// Guid:     ca761232-ed42-11ce-bacd-00aa0057b223 is equal to ca761232-ed42-11ce-bacd-00
// aa0057b223
// The following types are not CLS-compliant:
// SByte:    8 is equal to 8
// UInt16:   9 is equal to 9
// UInt32:   10 is equal to 10
// UInt64:   11 is equal to 11

' This example demonstrates the generic and non-generic versions of the 
' CompareTo method for several base types.
' The non-generic version takes a parameter of type Object, while the generic
' version takes a type-specific parameter, such as Boolean, Int32, or Double.

Class Sample
   Public Shared Sub Main()
      Dim nl As String = Environment.NewLine
      Dim msg As String = _
          "{0}The following is the result of using the generic and non-generic{0}" & _
          "versions of the CompareTo method for several base types:{0}"
      
      Dim now As DateTime = DateTime.Now
      ' Time span = 11 days, 22 hours, 33 minutes, 44 seconds
      Dim tsX As New TimeSpan(11, 22, 33, 44)
      ' Version = 1.2.333.4
      Dim versX As New Version("1.2.333.4")
      ' Guid = CA761232-ED42-11CE-BACD-00AA0057B223
      Dim guidX As New Guid("{CA761232-ED42-11CE-BACD-00AA0057B223}")
      
      Dim a1 As [Boolean] = True,    a2 As [Boolean] = True
      Dim b1 As [Byte] = 1,          b2 As [Byte] = 1
      Dim c1 As Int16 = -2,          c2 As Int16 = 2
      Dim d1 As Int32 = 3,           d2 As Int32 = 3
      Dim e1 As Int64 = 4,           e2 As Int64 = -4
      Dim f1 As [Decimal] = -5.5D,   f2 As [Decimal] = 5.5D
      Dim g1 As [Single] = 6.6F,     g2 As [Single] = 6.6F
      Dim h1 As [Double] = 7.7,      h2 As [Double] = -7.7
      Dim i1 As [Char] = "A"c,       i2 As [Char] = "A"c
      Dim j1 As String = "abc",      j2 As String = "abc"
      Dim k1 As DateTime = now,      k2 As DateTime = now
      Dim l1 As TimeSpan = tsX,      l2 As TimeSpan = tsX
      Dim m1 As Version = versX,     m2 As New Version("2.0")
      Dim n1 As Guid = guidX,        n2 As Guid = guidX
      
      ' The following types are not CLS-compliant.
      ' SByte, UInt16, UInt32, UInt64

      Console.WriteLine(msg, nl)
      Try
         ' The second and third Show method call parameters are automatically boxed because
         ' the second and third Show method declaration arguments expect type Object.

         Show("Boolean:  ", a1, a2, a1.CompareTo(a2), a1.CompareTo(CObj(a2)))
         Show("Byte:     ", b1, b2, b1.CompareTo(b2), b1.CompareTo(CObj(b2)))
         Show("Int16:    ", c1, c2, c1.CompareTo(c2), c1.CompareTo(CObj(c2)))
         Show("Int32:    ", d1, d2, d1.CompareTo(d2), d1.CompareTo(CObj(d2)))
         Show("Int64:    ", e1, e2, e1.CompareTo(e2), e1.CompareTo(CObj(e2)))
         Show("Decimal:  ", f1, f2, f1.CompareTo(f2), f1.CompareTo(CObj(f2)))
         Show("Single:   ", g1, g2, g1.CompareTo(g2), g1.CompareTo(CObj(g2)))
         Show("Double:   ", h1, h2, h1.CompareTo(h2), h1.CompareTo(CObj(h2)))
         Show("Char:     ", i1, i2, i1.CompareTo(i2), i1.CompareTo(CObj(i2)))
         Show("String:   ", j1, j2, j1.CompareTo(j2), j1.CompareTo(CObj(j2)))
         Show("DateTime: ", k1, k2, k1.CompareTo(k2), k1.CompareTo(CObj(k2)))
         Show("TimeSpan: ", l1, l2, l1.CompareTo(l2), l1.CompareTo(CObj(l2)))
         Show("Version:  ", m1, m2, m1.CompareTo(m2), m1.CompareTo(CObj(m2)))
         Show("Guid:     ", n1, n2, n1.CompareTo(n2), n1.CompareTo(CObj(n2)))
         '
         Console.WriteLine("{0}The following types are not CLS-compliant:", nl)
         Console.WriteLine("SByte, UInt16, UInt32, UInt64")

      Catch e As Exception
         Console.WriteLine(e)
      End Try
   End Sub
   
   Public Shared Sub Show(caption As String, var1 As [Object], var2 As [Object], _
                          resultGeneric As Integer, resultNonGeneric As Integer)
      Dim relation As String
      
      Console.Write(caption)
      If resultGeneric = resultNonGeneric Then
         If resultGeneric < 0 Then
            relation = "less than"
         ElseIf resultGeneric > 0 Then
            relation = "greater than"
         Else
            relation = "equal to"
         End If
         Console.WriteLine("{0} is {1} {2}", var1, relation, var2)
      
      ' The following condition will never occur because the generic and non-generic
      ' CompareTo methods are equivalent.

      Else
         Console.WriteLine("Generic CompareTo = {0}; non-generic CompareTo = {1}", _
                            resultGeneric, resultNonGeneric)
      End If
   End Sub
End Class
'
'This example produces the following results:
'
'The following is the result of using the generic and non-generic versions of the
'CompareTo method for several base types:
'
'Boolean:  True is equal to True
'Byte:     1 is equal to 1
'Int16:    -2 is less than 2
'Int32:    3 is equal to 3
'Int64:    4 is greater than -4
'Decimal:  -5.5 is less than 5.5
'Single:   6.6 is equal to 6.6
'Double:   7.7 is greater than -7.7
'Char:     A is equal to A
'String:   abc is equal to abc
'DateTime: 12/1/2003 5:37:46 PM is equal to 12/1/2003 5:37:46 PM
'TimeSpan: 11.22:33:44 is equal to 11.22:33:44
'Version:  1.2.333.4 is less than 2.0
'Guid:     ca761232-ed42-11ce-bacd-00aa0057b223 is equal to ca761232-ed42-11ce-bacd-00
'aa0057b223
'
'The following types are not CLS-compliant:
'SByte, UInt16, UInt32, UInt64
'

Commenti

Questo metodo esegue un confronto di parole (con distinzione tra maiuscole e minuscole e con distinzione tra impostazioni cultura) usando le impostazioni cultura correnti. Per altre informazioni sugli ordinali di parole, stringhe e ordinali, vedere System.Globalization.CompareOptions.

Attenzione

Il CompareTo metodo è stato progettato principalmente per l'uso nelle operazioni di ordinamento o di alfabetizzazione. Non deve essere usato quando lo scopo principale della chiamata al metodo consiste nel determinare se due stringhe sono equivalenti. Per determinare se due stringhe sono equivalenti, chiamare il Equals metodo .

Per altre informazioni sul comportamento di questo metodo, vedere la sezione Osservazioni del Compare(String, String) metodo .

Questo metodo implementa l'interfaccia System.IComparable<T> ed esegue prestazioni leggermente migliori rispetto al metodo , perché non è necessario determinare se l'argomento strB è un tipo valore modificabile che deve essere sottoposto a boxing e non deve eseguire il cast del String.CompareTo(Object) relativo parametro da un Object oggetto a un oggetto String.

Note per i chiamanti

I set di caratteri includono caratteri ignorabili. Il CompareTo(String) metodo non considera tali caratteri quando esegue un confronto con distinzione tra impostazioni cultura. Ad esempio, se il codice seguente viene eseguito in .NET Framework 4 o versione successiva, un confronto tra "animale" e "ani-mal" (usando un trattino morbido o U+00AD) indica che le due stringhe sono equivalenti.

using System;

public class Example
{
   public static void Main()
   {
      string s1 = "ani\u00ADmal";
      string s2 = "animal";
      
      Console.WriteLine("Comparison of '{0}' and '{1}': {2}", 
                        s1, s2, s1.CompareTo(s2));
   }
}
// The example displays the following output:
//       Comparison of 'ani-mal' and 'animal': 0

let s1 = "ani\u00ADmal"
let s2 = "animal"

printfn $"Comparison of '{s1}' and '{s2}': {s1.CompareTo s2}"
// The example displays the following output:
//       Comparison of 'ani-mal' and 'animal': 0

Module Example
   Public Sub Main()
      Dim s1 As String = "ani" + ChrW(&h00AD) + "mal"
      Dim s2 As String = "animal"
      
      Console.WriteLine("Comparison of '{0}' and '{1}': {2}", 
                        s1, s2, s1.CompareTo(s2))
  End Sub
End Module
' The example displays the following output:
'       Comparison of 'ani-mal' and 'animal': 0

Per riconoscere i caratteri ignorabili in un confronto tra stringhe, chiamare il CompareOrdinal(String, String) metodo .

Vedi anche

Si applica a