Double.NaN Feld

Definition

Stellt einen Wert dar, der keine Zahl ist (NaN).Represents a value that is not a number (NaN). Dieses Feld ist konstant.This field is constant.

public: double NaN = NaN;
public const double NaN = NaN;
val mutable NaN : double
Public Const NaN As Double  = NaN

Feldwert

Double

Beispiele

Im folgenden Beispiel wird die Verwendung von NaN veranschaulicht:The following example illustrates the use of NaN:

Double zero = 0;

// This condition will return false.
if ( (0 / zero) == Double::NaN )
{
   Console::WriteLine( "0 / 0 can be tested with Double::NaN." );
}
else
{
   Console::WriteLine( "0 / 0 cannot be tested with Double::NaN; use Double::IsNan() instead." );
}
Double zero = 0;
  
// This condition will return false.
if ((0 / zero) == Double.NaN)
   Console.WriteLine("0 / 0 can be tested with Double.NaN.");
else
   Console.WriteLine("0 / 0 cannot be tested with Double.NaN; use Double.IsNan() instead.");
Dim zero As Double = 0

' This condition will return false.
If (0 / zero) = Double.NaN Then
    Console.WriteLine("0 / 0 can be tested with Double.NaN.")
Else
    Console.WriteLine("0 / 0 cannot be tested with Double.NaN; use Double.IsNan() instead.")
End If

Hinweise

Eine Methode oder ein Operator gibt zurück, NaN Wenn das Ergebnis eines Vorgangs nicht definiert ist.A method or operator returns NaN when the result of an operation is undefined. Das Ergebnis der Division von NULL durch Null ist beispielsweise NaN , wie im folgenden Beispiel gezeigt.For example, the result of dividing zero by zero is NaN, as the following example shows. (Beachten Sie jedoch, dass die Aufteilung einer Zahl ungleich NULL durch Null entweder oder zurückgibt PositiveInfinity NegativeInfinity , abhängig vom Vorzeichen des Divisors.)(But note that dividing a non-zero number by zero returns either PositiveInfinity or NegativeInfinity, depending on the sign of the divisor.)

double zero = 0.0;
Console.WriteLine("{0} / {1} = {2}", zero, zero, zero/zero);
// The example displays the following output:
//         0 / 0 = NaN
Dim zero As Double = 0
Console.WriteLine("{0} / {1} = {2}", zero, zero, zero/zero)
' The example displays the following output:
'         0 / 0 = NaN

Außerdem gibt ein Methodenaufrufe mit einem NaN Wert oder einem Vorgang für einen NaN Wert zurück NaN , wie im folgenden Beispiel gezeigt.In addition, a method call with a NaN value or an operation on a NaN value returns NaN, as the following example shows.

double nan1 = Double.NaN;

Console.WriteLine("{0} + {1} = {2}", 3, nan1, 3 + nan1);
Console.WriteLine("Abs({0}) = {1}", nan1, Math.Abs(nan1));
// The example displays the following output:
//       3 + NaN = NaN
//       Abs(NaN) = NaN
Dim nan1 As Double = Double.NaN

Console.WriteLine("{0} + {1} = {2}", 3, nan1, 3 + nan1)
Console.WriteLine("Abs({0}) = {1}", nan1, Math.Abs(nan1))
' The example displays the following output:
'       3 + NaN = NaN
'       Abs(NaN) = NaN

Verwenden Sie die- IsNaN Methode, um zu bestimmen, ob ein Wert keine Zahl ist.Use the IsNaN method to determine whether a value is not a number. Der- Equality Operator betrachtet zwei Werte, die ungleich zueinander sind NaN .The Equality operator considers two NaN values to be unequal to one another. Im Allgemeinen können Double Operatoren nicht zum Vergleichen Double.NaN mit anderen Werten verwendet werden Double , obwohl Vergleichsmethoden (z Equals . b. und CompareTo ) möglich sind.In general, Double operators cannot be used to compare Double.NaN with other Double values, although comparison methods (such as Equals and CompareTo) can. Das folgende Beispiel veranschaulicht den Unterschied im Verhalten zwischen Double Vergleichs Operatoren und Methoden.The following example illustrates the difference in behavior between Double comparison operators and methods.

using System;

public class Example
{
   public static void Main()
   {
      Console.WriteLine("NaN == NaN: {0}", Double.NaN == Double.NaN);
      Console.WriteLine("NaN != NaN: {0}", Double.NaN != Double.NaN);
      Console.WriteLine("NaN.Equals(NaN): {0}", Double.NaN.Equals(Double.NaN));
      Console.WriteLine("! NaN.Equals(NaN): {0}", ! Double.NaN.Equals(Double.NaN));
      Console.WriteLine("IsNaN: {0}", Double.IsNaN(Double.NaN));

      Console.WriteLine("\nNaN > NaN: {0}", Double.NaN > Double.NaN);
      Console.WriteLine("NaN >= NaN: {0}", Double.NaN >= Double.NaN);
      Console.WriteLine("NaN < NaN: {0}", Double.NaN < Double.NaN);
      Console.WriteLine("NaN < 100.0: {0}", Double.NaN < 100.0);
      Console.WriteLine("NaN <= 100.0: {0}", Double.NaN <= 100.0);
      Console.WriteLine("NaN >= 100.0: {0}", Double.NaN > 100.0);
      Console.WriteLine("NaN.CompareTo(NaN): {0}", Double.NaN.CompareTo(Double.NaN));
      Console.WriteLine("NaN.CompareTo(100.0): {0}", Double.NaN.CompareTo(100.0));
      Console.WriteLine("(100.0).CompareTo(Double.NaN): {0}", (100.0).CompareTo(Double.NaN));
   }
}
// The example displays the following output:
//       NaN == NaN: False
//       NaN != NaN: True
//       NaN.Equals(NaN): True
//       ! NaN.Equals(NaN): False
//       IsNaN: True
//
//       NaN > NaN: False
//       NaN >= NaN: False
//       NaN < NaN: False
//       NaN < 100.0: False
//       NaN <= 100.0: False
//       NaN >= 100.0: False
//       NaN.CompareTo(NaN): 0
//       NaN.CompareTo(100.0): -1
//       (100.0).CompareTo(Double.NaN): 1
Module Example
   Public Sub Main()
      Console.WriteLine("NaN = NaN: {0}", Double.NaN = Double.NaN) 
      Console.WriteLine("NaN <> NaN: {0}", Double.NaN <> Double.NaN) 
      Console.WriteLine("NaN.Equals(NaN): {0}", Double.NaN.Equals(Double.NaN)) 
      Console.WriteLine("Not NaN.Equals(NaN): {0}", Not Double.NaN.Equals(Double.NaN)) 
      Console.WriteLine("IsNaN: {0}", Double.IsNaN(Double.NaN))
      Console.WriteLine()
      Console.WriteLine("NaN > NaN: {0}", Double.NaN > 100.0) 
      Console.WriteLine("NaN >= NaN: {0}", Double.NaN >= 100.0) 
      Console.WriteLine("NaN < NaN: {0}", Double.NaN < Double.NaN)
      Console.WriteLine("NaN < 100.0: {0}", Double.NaN < 100.0) 
      Console.WriteLine("NaN <= 100.0: {0}", Double.NaN <= 100.0) 
      Console.WriteLine("NaN >= 100.0: {0}", Double.NaN > 100.0)
      Console.WriteLine("NaN.CompareTo(NaN): {0}", Double.NaN.CompareTo(Double.Nan)) 
      Console.WriteLine("NaN.CompareTo(100.0): {0}", Double.NaN.CompareTo(100.0)) 
      Console.WriteLine("(100.0).CompareTo(Double.NaN): {0}", (100.0).CompareTo(Double.NaN)) 
   End Sub
End Module
' The example displays the following output:
'       NaN == NaN: False
'       NaN != NaN: True
'       NaN.Equals(NaN): True
'       ! NaN.Equals(NaN): False
'       IsNaN: True
'
'       NaN > NaN: False
'       NaN >= NaN: False
'       NaN < NaN: False
'       NaN < 100.0: False
'       NaN <= 100.0: False
'       NaN >= 100.0: False
'       NaN.CompareTo(NaN): 0
'       NaN.CompareTo(100.0): -1
'       (100.0).CompareTo(Double.NaN): 1

Gilt für:

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