Double.NaN Field

Represents a value that is not a number (NaN). This field is constant.

Namespace: System
Assembly: mscorlib (in mscorlib.dll)

literal double NaN
public static final double NaN
public const var NaN : double

The value of this constant is the result of dividing zero by zero.

This constant is returned when the result of an operation is undefined.

Use IsNaN to determine whether a value is not a number. It is not possible to determine whether a value is not a number by comparing it to another value equal to NaN.

The following code 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." );
   Console::WriteLine( "0 / 0 cannot be tested with Double::NaN; use Double::IsNan() instead." );

Double zero = new Double(0);

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

Windows 98, Windows 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.

.NET Framework

Supported in: 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 2.0, 1.0