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Single.NaN Champ

Définition

Représente une valeur autre qu'un nombre (NaN). Ce champ est constant.

public: float NaN = NaN;
public const float NaN = NaN;
val mutable NaN : single
Public Const NaN As Single  = NaN

Valeur de champ

Value = NaN

Exemples

L’exemple suivant illustre la NaN constante.

Single zero = 0;

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

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

// This condition will return false.
if 0f / zero = Single.NaN then
    printfn "0 / 0 can be tested with Single.NaN."
else
    printfn "0 / 0 cannot be tested with Single.NaN use Single.IsNan() instead."
Dim zero As Single = 0

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

Remarques

Une méthode ou un opérateur retourne NaN lorsque le résultat d’une opération n’est pas défini. Par exemple, le résultat de la division de zéro par zéro est NaN, comme le montre l’exemple suivant. (Mais notez que la division d’un nombre autre que zéro par zéro renvoie PositiveInfinity ou NegativeInfinity, en fonction du signe du diviseur.)

float zero = 0.0f;
Console.WriteLine("{0} / {1} = {2}", zero, zero, zero/zero);
// The example displays the following output:
//         0 / 0 = NaN
let zero = 0f
printfn $"{zero} / {zero} = {zero / zero}"
// The example displays the following output:
//         0 / 0 = NaN
Dim zero As Single = 0
Console.WriteLine("{0} / {1} = {2}", zero, zero, zero/zero)
' The example displays the following output:
'         0 / 0 = NaN

En outre, un appel de méthode avec une NaN valeur ou une opération sur une NaN valeur retourne NaN, comme le montre l’exemple suivant.

float nan1 = Single.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
let nan1 = Single.NaN

printfn $"{3} + {nan1} = {3f + nan1}"
printfn $"Abs({nan1}) = {abs nan1}"
// The example displays the following output:
//       3 + NaN = NaN
//       Abs(NaN) = NaN
Dim nan1 As Single = Single.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

Utilisez la IsNaN méthode pour déterminer si une valeur n’est pas un nombre. En général, Single les opérateurs ne peuvent pas être utilisés pour comparer Single.NaN avec d’autres Single valeurs, bien que les méthodes de comparaison (telles que Equals et CompareTo) puissent le faire. L’exemple suivant illustre la différence de comportement entre Single les opérateurs de comparaison et les méthodes.

using System;

public class Example
{
   public static void Main()
   {
      Console.WriteLine("NaN == NaN: {0}", Single.NaN == Single.NaN); 
      Console.WriteLine("NaN != NaN: {0}", Single.NaN != Single.NaN); 
      Console.WriteLine("NaN.Equals(NaN): {0}", Single.NaN.Equals(Single.NaN)); 
      Console.WriteLine("! NaN.Equals(NaN): {0}", ! Single.NaN.Equals(Single.NaN)); 
      Console.WriteLine("IsNaN: {0}", Double.IsNaN(Double.NaN));
      
      Console.WriteLine("\nNaN > NaN: {0}", Single.NaN > Single.NaN); 
      Console.WriteLine("NaN >= NaN: {0}", Single.NaN >= Single.NaN); 
      Console.WriteLine("NaN < NaN: {0}", Single.NaN < Single.NaN);
      Console.WriteLine("NaN < 100.0: {0}", Single.NaN < 100.0f); 
      Console.WriteLine("NaN <= 100.0: {0}", Single.NaN <= 100.0f); 
      Console.WriteLine("NaN >= 100.0: {0}", Single.NaN > 100.0f);
      Console.WriteLine("NaN.CompareTo(NaN): {0}", Single.NaN.CompareTo(Single.NaN)); 
      Console.WriteLine("NaN.CompareTo(100.0): {0}", Single.NaN.CompareTo(100.0f)); 
      Console.WriteLine("(100.0).CompareTo(Single.NaN): {0}", (100.0f).CompareTo(Single.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(Single.NaN): 1
open System

printfn $"NaN == NaN: {Single.NaN = Single.NaN}"
printfn $"NaN != NaN: {Single.NaN <> Single.NaN}"
printfn $"NaN.Equals(NaN): {Single.NaN.Equals Single.NaN}"
printfn $"! NaN.Equals(NaN): {not (Single.NaN.Equals Single.NaN)}"
printfn $"IsNaN: {Double.IsNaN Double.NaN}"

printfn $"\nNaN > NaN: {Single.NaN > Single.NaN}"
printfn $"NaN >= NaN: {Single.NaN >= Single.NaN}"
printfn $"NaN < NaN: {Single.NaN < Single.NaN}"
printfn $"NaN < 100.0: {Single.NaN < 100f}"
printfn $"NaN <= 100.0: {Single.NaN <= 100f}"
printfn $"NaN >= 100.0: {Single.NaN > 100f}"
printfn $"NaN.CompareTo(NaN): {Single.NaN.CompareTo Single.NaN}"
printfn $"NaN.CompareTo(100.0): {Single.NaN.CompareTo 100f}"
printfn $"(100.0).CompareTo(Single.NaN): {100f.CompareTo Single.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(Single.NaN): 1
Module Example
   Public Sub Main()
      Console.WriteLine("NaN = NaN: {0}", Single.NaN = Single.NaN) 
      Console.WriteLine("NaN <> NaN: {0}", Single.NaN <> Single.NaN) 
      Console.WriteLine("NaN.Equals(NaN): {0}", Single.NaN.Equals(Single.NaN)) 
      Console.WriteLine("Not NaN.Equals(NaN): {0}", Not Single.NaN.Equals(Single.NaN)) 
      Console.WriteLine("IsNaN: {0}", Double.IsNaN(Double.NaN))
      Console.WriteLine()
      Console.WriteLine("NaN > NaN: {0}", Single.NaN > 100.0f) 
      Console.WriteLine("NaN >= NaN: {0}", Single.NaN >= 100.0f) 
      Console.WriteLine("NaN < NaN: {0}", Single.NaN < Single.NaN)
      Console.WriteLine("NaN < 100.0: {0}", Single.NaN < 100.0f) 
      Console.WriteLine("NaN <= 100.0: {0}", Single.NaN <= 100.0f) 
      Console.WriteLine("NaN >= 100.0: {0}", Single.NaN > 100.0f)
      Console.WriteLine("NaN.CompareTo(NaN): {0}", Single.NaN.CompareTo(Single.Nan)) 
      Console.WriteLine("NaN.CompareTo(100.0): {0}", Single.NaN.CompareTo(100.0f)) 
      Console.WriteLine("(100.0).CompareTo(Single.NaN): {0}", (100.0f).CompareTo(Single.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(Single.NaN): 1

S’applique à

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