Double.CompareTo Double.CompareTo Double.CompareTo Double.CompareTo Method

Definition

Vergleicht diese Instanz mit einem angegebenen Objekt oder einem Double-Objekt und gibt eine ganze Zahl zurück, die angibt, ob der Wert dieser Instanz kleiner oder größer als der Wert des angegebenen Objekts bzw. des Double-Objekts ist oder mit diesem übereinstimmt.Compares this instance to a specified object or Double object and returns an integer that indicates whether the value of this instance is less than, equal to, or greater than the value of the specified object or Double object.

Überlädt

CompareTo(Double) CompareTo(Double) CompareTo(Double) CompareTo(Double)

Vergleicht diese Instanz mit einer angegebenen Gleitkommazahl mit doppelter Genauigkeit und gibt eine Ganzzahl zurück, die angibt, ob der Wert dieser Instanz kleiner oder größer als der Wert der angegebenen Gleitkommazahl mit doppelter Genauigkeit ist oder mit dieser übereinstimmt.Compares this instance to a specified double-precision floating-point number and returns an integer that indicates whether the value of this instance is less than, equal to, or greater than the value of the specified double-precision floating-point number.

CompareTo(Object) CompareTo(Object) CompareTo(Object) CompareTo(Object)

Vergleicht diese Instanz mit einem angegebenen Objekt und gibt eine ganze Zahl zurück, die angibt, ob der Wert dieser Instanz kleiner oder größer als der Wert des angegebenen Objekts ist oder mit diesem übereinstimmt.Compares this instance to a specified object and returns an integer that indicates whether the value of this instance is less than, equal to, or greater than the value of the specified object.

CompareTo(Double) CompareTo(Double) CompareTo(Double) CompareTo(Double)

Vergleicht diese Instanz mit einer angegebenen Gleitkommazahl mit doppelter Genauigkeit und gibt eine Ganzzahl zurück, die angibt, ob der Wert dieser Instanz kleiner oder größer als der Wert der angegebenen Gleitkommazahl mit doppelter Genauigkeit ist oder mit dieser übereinstimmt.Compares this instance to a specified double-precision floating-point number and returns an integer that indicates whether the value of this instance is less than, equal to, or greater than the value of the specified double-precision floating-point number.

public:
 virtual int CompareTo(double value);
public int CompareTo (double value);
abstract member CompareTo : double -> int
override this.CompareTo : double -> int
Public Function CompareTo (value As Double) As Integer

Parameter

value
Double Double Double Double

Eine Gleitkommazahl mit doppelter Genauigkeit, mit der der Vergleich erfolgen soll.A double-precision floating-point number to compare.

Gibt zurück

Eine Zahl mit Vorzeichen, die das Verhältnis zwischen dem Wert dieser Instanz und value angibt.A signed number indicating the relative values of this instance and value.

RückgabewertReturn Value BESCHREIBUNGDescription
Kleiner als 0 (null)Less than zero Diese Instanz ist kleiner als value.This instance is less than value. - oder --or- Diese Instanz ist keine Zahl (NaN), und value ist eine Zahl.This instance is not a number (NaN) and value is a number.
ZeroZero Diese Instanz ist gleich value.This instance is equal to value. - oder --or- Sowohl diese Instanz als auch value sind keine Zahl (NaN), PositiveInfinity, oder NegativeInfinity.Both this instance and value are not a number (NaN), PositiveInfinity, or NegativeInfinity.
Größer als 0 (null)Greater than zero Diese Instanz ist größer als value.This instance is greater than value. - oder --or- Diese Instanz ist eine Zahl, und value ist keine Zahl (NaN).This instance is a number and value is not a number (NaN).

Implementiert

Beispiele

Im folgenden Codebeispiel werden generische und nicht generische Versionen der CompareTo -Methode für verschiedene Wert-und Verweis Typen veranschaulicht.The following code example demonstrates generic and nongeneric versions of the CompareTo method for several value and reference types.

// 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.

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
'

Hinweise

Werte müssen identisch sein, damit Sie als gleich betrachtet werden.Values must be identical to be considered equal. Insbesondere wenn Gleit Komma Werte von mehreren mathematischen Operationen abhängen, ist es üblich, dass Sie Genauigkeit verlieren und ihre Werte nahezu identisch sind, mit Ausnahme der am wenigsten signifikanten Ziffern.Particularly when floating-point values depend on multiple mathematical operations, it is common for them to lose precision and for their values to be nearly identical except for their least significant digits. Aus diesem Grund mag der Rückgabewert CompareTo der Methode zu Zeiten überraschend erscheinen.Because of this, the return value of the CompareTo method at times may seem surprising. Beispielsweise sollte die Multiplikation mit einem bestimmten Wert, gefolgt von der Division durch denselben Wert, den ursprünglichen Wert ergeben.For example, multiplication by a particular value followed by division by the same value should produce the original value. Im folgenden Beispiel erweist sich der berechnete Wert jedoch als größer als der ursprüngliche Wert.In the following example, however, the computed value turns out to be greater than the original value. Wenn alle signifikanten Ziffern der beiden Werte mithilfe der standardmäßigen numerischen Format Zeichenfolge "R" angezeigt werden, wird angegeben, dass der berechnete Wert vom ursprünglichen Wert in den geringsten Ziffern abweicht.Showing all significant digits of the two values by using the "R" standard numeric format string indicates that the computed value differs from the original value in its least significant digits. Informationen zur Behandlung solcher Vergleiche finden Sie im Abschnitt "Hinweise" der Equals(Double) -Methode.For information on handling such comparisons, see the Remarks section of the Equals(Double) method.

using System;

public class Example
{
   public static void Main()
   {
       double value1 = 6.185;
       double value2 = value1 * .1 / .1;
       Console.WriteLine("Comparing {0} and {1}: {2}\n",
                         value1, value2, value1.CompareTo(value2));
       Console.WriteLine("Comparing {0:R} and {1:R}: {2}",
                         value1, value2, value1.CompareTo(value2));
   }
}
// The example displays the following output:
//       Comparing 6.185 and 6.185: -1
//       
//       Comparing 6.185 and 6.1850000000000005: -1
Module Example
   Public Sub Main()
       Dim value1 As Double = 6.185
       Dim value2 As Double = value1 * .1 / .1
       Console.WriteLine("Comparing {0} and {1}: {2}",
                         value1, value2, value1.CompareTo(value2))
       Console.WriteLine()
       Console.WriteLine("Comparing {0:R} and {1:R}: {2}",
                         value1, value2, value1.CompareTo(value2))
   End Sub
End Module
' The example displays the following output:
'       Comparing 6.185 and 6.185: -1
'       
'       Comparing 6.185 and 6.1850000000000005: -1

Diese Methode implementiert die System.IComparable<T> -Schnittstelle und führt eine etwas Double.CompareTo bessere Leistung als die-Methode aus, da value der-Parameter nicht in ein-Objekt konvertiert werden muss.This method implements the System.IComparable<T> interface and performs slightly better than the Double.CompareTo method because it does not have to convert the value parameter to an object.

Beachten Sie, dass ein Objekt, dessen Wert NaN nicht gleich einem anderen Objekt ist, dessen Wert ist NaN (selbst), erfordert, IComparable<T> dass A.CompareTo(A) die-Schnittstelle NULL zurückgibt.Note that, although an object whose value is NaN is not considered equal to another object whose value is NaN (even itself), the IComparable<T> interface requires that A.CompareTo(A) return zero.

ErweiterungskonvertierungenWidening Conversions

Abhängig von ihrer Programmiersprache kann es möglich sein, eine CompareTo Methode zu codieren, bei der der Parametertyp weniger Bits (ist schmaler) als der Instanztyp aufweist.Depending on your programming language, it might be possible to code a CompareTo method where the parameter type has fewer bits (is narrower) than the instance type. Dies ist möglich, weil einige Programmiersprachen eine implizite erweiternde Konvertierung durchführen, die den Parameter als Typ mit so vielen Bits wie die Instanz darstellt.This is possible because some programming languages perform an implicit widening conversion that represents the parameter as a type with as many bits as the instance.

Angenommen, der Instanztyp ist Double , und der Parametertyp ist. Int32For example, suppose the instance type is Double and the parameter type is Int32. Der Microsoft C# -Compiler generiert Anweisungen, um den Wert des-Parameters Double als-Objekt darzustellen, Double.CompareTo(Double) und generiert dann eine-Methode, die die Werte der-Instanz und die erweiterte Darstellung des-Parameters vergleicht.The Microsoft C# compiler generates instructions to represent the value of the parameter as a Double object, then generates a Double.CompareTo(Double) method that compares the values of the instance and the widened representation of the parameter.

Überprüfen Sie die Dokumentation der Programmiersprache, um zu bestimmen, ob der Compiler implizite erweiternde Konvertierungen numerischer Typen durchführt.Consult your programming language's documentation to determine if its compiler performs implicit widening conversions of numeric types. Weitere Informationen finden Sie im Thema Typkonvertierungs Tabellen .For more information, see the Type Conversion Tables topic.

Genauigkeit in vergleichenPrecision in Comparisons

Die Genauigkeit von Gleit Komma Zahlen jenseits der dokumentierten Genauigkeit ist spezifisch für die Implementierung und die Version der .NET Framework.The precision of floating-point numbers beyond the documented precision is specific to the implementation and version of the .NET Framework. Folglich kann sich ein Vergleich zweier bestimmter Zahlen zwischen den Versionen der .NET Framework ändern, da sich die Genauigkeit der internen Darstellung der Zahlen ändern kann.Consequently, a comparison of two particular numbers might change between versions of the .NET Framework because the precision of the numbers' internal representation might change.

Siehe auch

CompareTo(Object) CompareTo(Object) CompareTo(Object) CompareTo(Object)

Vergleicht diese Instanz mit einem angegebenen Objekt und gibt eine ganze Zahl zurück, die angibt, ob der Wert dieser Instanz kleiner oder größer als der Wert des angegebenen Objekts ist oder mit diesem übereinstimmt.Compares this instance to a specified object and returns an integer that indicates whether the value of this instance is less than, equal to, or greater than the value of the specified object.

public:
 virtual int CompareTo(System::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

Parameter

value
Object Object Object Object

Ein Vergleichsobjekt oder null.An object to compare, or null.

Gibt zurück

Eine Zahl mit Vorzeichen, die das Verhältnis zwischen dem Wert dieser Instanz und value angibt.A signed number indicating the relative values of this instance and value.

WertValue BeschreibungDescription
Eine negative ganze ZahlA negative integer Diese Instanz ist kleiner als value.This instance is less than value. - oder --or- Diese Instanz ist keine Zahl (NaN), und value ist eine Zahl.This instance is not a number (NaN) and value is a number.
ZeroZero Diese Instanz ist gleich value.This instance is equal to value. - oder --or- Diese Instanz und value sind beide Double.NaN, PositiveInfinity oder NegativeInfinityThis instance and value are both Double.NaN, PositiveInfinity, or NegativeInfinity
Eine positive ganze ZahlA positive integer Diese Instanz ist größer als value.This instance is greater than value. - oder --or- Diese Instanz ist eine Zahl, und value ist keine Zahl (NaN).This instance is a number and value is not a number (NaN). - oder --or- value ist null.value is null.

Implementiert

Ausnahmen

Beispiele

Im folgenden Codebeispiel wird die Verwendung von CompareTo im Kontext von Doubleveranschaulicht.The following code example illustrates the use of CompareTo in the context of Double.

obj1 = (Double)450;
if ( a.CompareTo( obj1 ) < 0 )
{
   Console::WriteLine( "{0} is less than {1}.", a, obj1 );
}

if ( a.CompareTo( obj1 ) > 0 )
{
   Console::WriteLine( "{0} is greater than {1}.", a, obj1 );
}

if ( a.CompareTo( obj1 ) == 0 )
{
   Console::WriteLine( "{0} equals {1}.", a, obj1 );
}
obj1 = (Double)450;
      
if (a.CompareTo(obj1) < 0) 
   Console.WriteLine("{0} is less than {1}.", a.ToString(), obj1.ToString());

if (a.CompareTo(obj1) > 0) 
   Console.WriteLine("{0} is greater than {1}.", a.ToString(), obj1.ToString());

if (a.CompareTo(obj1) == 0) 
   Console.WriteLine("{0} equals {1}.", a.ToString(), obj1.ToString());
Obj1 = CType(450, Double)

If A.CompareTo(Obj1) < 0 Then
    Console.WriteLine(A.ToString() + " is less than " + Obj1.ToString() + ".")
End If

If (A.CompareTo(Obj1) > 0) Then
    Console.WriteLine(A.ToString() + " is greater than " + Obj1.ToString() + ".")
End If

If (A.CompareTo(Obj1) = 0) Then
    Console.WriteLine(A.ToString() + " equals " + Obj1.ToString() + ".")
End If

Hinweise

Der value -Parameter muss null oder eine Instanz von Doublesein. andernfalls wird eine Ausnahme ausgelöst.The value parameter must be null or an instance of Double; otherwise, an exception is thrown. Jede Instanz von Doublegilt unabhängig von ihrem Wert als größer als. nullAny instance of Double, regardless of its value, is considered greater than null.

Werte müssen identisch sein, damit Sie als gleich betrachtet werden.Values must be identical to be considered equal. Insbesondere wenn Gleit Komma Werte von mehreren mathematischen Operationen abhängen, ist es üblich, dass Sie Genauigkeit verlieren und ihre Werte nahezu identisch sind, mit Ausnahme der am wenigsten signifikanten Ziffern.Particularly when floating-point values depend on multiple mathematical operations, it is common for them to lose precision and for their values to be nearly identical except for their least significant digits. Aus diesem Grund mag der Rückgabewert CompareTo der Methode zu Zeiten überraschend erscheinen.Because of this, the return value of the CompareTo method at times may seem surprising. Beispielsweise sollte die Multiplikation mit einem bestimmten Wert, gefolgt von der Division durch denselben Wert, den ursprünglichen Wert ergeben.For example, multiplication by a particular value followed by division by the same value should produce the original value. Im folgenden Beispiel erweist sich der berechnete Wert jedoch als größer als der ursprüngliche Wert.In the following example, however, the computed value turns out to be greater than the original value. Wenn alle signifikanten Ziffern der beiden Werte mithilfe der standardmäßigen numerischen Format Zeichenfolge "R" angezeigt werden, wird angegeben, dass der berechnete Wert vom ursprünglichen Wert in den geringsten Ziffern abweicht.Showing all significant digits of the two values by using the "R" standard numeric format string indicates that the computed value differs from the original value in its least significant digits. Informationen zur Behandlung solcher Vergleiche finden Sie im Abschnitt "Hinweise" der Equals(Double) -Methode.For information on handling such comparisons, see the Remarks section of the Equals(Double) method.

using System;

public class Example
{
   public static void Main()
   {
       double value1 = 6.185;
       object value2 = value1 * .1 / .1;
       Console.WriteLine("Comparing {0} and {1}: {2}\n",
                         value1, value2, value1.CompareTo(value2));
       Console.WriteLine("Comparing {0:R} and {1:R}: {2}",
                         value1, value2, value1.CompareTo(value2));
   }
}
// The example displays the following output:
//       Comparing 6.185 and 6.185: -1
//       
//       Comparing 6.185 and 6.1850000000000005: -1
Module Example
   Public Sub Main()
       Dim value1 As Double = 6.185
       Dim value2 As Object = value1 * .1 / .1
       Console.WriteLine("Comparing {0} and {1}: {2}",
                         value1, value2, value1.CompareTo(value2))
       Console.WriteLine()
       Console.WriteLine("Comparing {0:R} and {1:R}: {2}",
                         value1, value2, value1.CompareTo(value2))
   End Sub
End Module
' The example displays the following output:
'       Comparing 6.185 and 6.185: -1
'       
'       Comparing 6.185 and 6.1850000000000005: -1

Diese Methode wird zur Unterstützung der IComparable -Schnittstelle implementiert.This method is implemented to support the IComparable interface. Beachten Sie, dass die NaN IComparable -Schnittstelle, obwohl nicht als gleich NaN wertig angesehen wird (selbst), erfordert, A.CompareTo(A) dass 0 (null) zurückgibt.Note that, although a NaN is not considered to be equal to another NaN (even itself), the IComparable interface requires that A.CompareTo(A) return zero.

Genauigkeit in vergleichenPrecision in Comparisons

Die Genauigkeit von Gleit Komma Zahlen jenseits der dokumentierten Genauigkeit ist spezifisch für die Implementierung und die Version der .NET Framework.The precision of floating-point numbers beyond the documented precision is specific to the implementation and version of the .NET Framework. Folglich kann sich ein Vergleich zweier bestimmter Zahlen zwischen den Versionen der .NET Framework ändern, da sich die Genauigkeit der internen Darstellung der Zahlen ändern kann.Consequently, a comparison of two particular numbers might change between versions of the .NET Framework because the precision of the numbers' internal representation might change.

Siehe auch

Gilt für: