Double.NaN Field
Definition
Important
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Represents a value that is not a number (NaN). This field is constant.
Value = NaNExamples
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.");
let zero = 0.
if 0. / zero = Double.NaN then
printfn "0 / 0 can be tested with Double.NaN."
printfn "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
Remarks
A method or operator returns NaN when the result of an operation is undefined. For example, the result of dividing zero by zero is NaN, as the following example shows. (However, 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
let zero = 0.0
printfn $"{zero} / {zero} = {zero / zero}"
Console.WriteLine("{0} / {1} = {2}", zero, zero, zero/zero)
' The example displays the following output:
' 0 / 0 = NaN
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));
// 3 + NaN = NaN
// Abs(NaN) = NaN
let nan1 = Double.NaN
printfn $"{3} + {nan1} = {3. + nan1}"
printfn $"abs({nan1}) = {abs nan1}"
// 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))
' 3 + NaN = NaN
' Abs(NaN) = NaN
using System;
public class Example
public static void Main()
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);
// 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
open System
printfn $"NaN = NaN: {Double.NaN = Double.NaN}"
printfn $"NaN <> NaN: {Double.NaN <> Double.NaN}"
printfn $"NaN.Equals(NaN): {Double.NaN.Equals Double.NaN}"
printfn $"not (NaN.Equals NaN): {not (Double.NaN.Equals Double.NaN)}"
printfn $"NaN >= NaN: {Double.NaN >= Double.NaN}"
printfn $"NaN < NaN: {Double.NaN < Double.NaN}"
printfn $"NaN < 100.0: {Double.NaN < 100.0}"
printfn $"NaN <= 100.0: {Double.NaN <= 100.0}"
printfn $"NaN >= 100.0: {Double.NaN > 100.0}"
printfn $"NaN.CompareTo(100.0): {Double.NaN.CompareTo 100.0}"
printfn $"(100.0).CompareTo(Double.NaN): {(100.0).CompareTo Double.NaN}"
// NaN = NaN: False
// NaN <> NaN: True
// not (NaN.Equals NaN): False
Module Example
Public Sub Main()
Console.WriteLine()
Console.WriteLine("NaN > NaN: {0}", Double.NaN > 100.0)
Console.WriteLine("NaN >= NaN: {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 >= 100.0: {0}", Double.NaN > 100.0)
End Sub
End Module
' 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