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Double.NaN Field

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

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

public const double NaN
public static final double NaN
public const var NaN : double
Not applicable.

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.");
} 
else 
{
    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 {
    Console.WriteLine(
        "0 / 0 cannot be tested with Double.NaN; " 
        + "use Double.IsNan() instead.");
}

Windows 98, Windows Server 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 Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0, 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 2.0, 1.0

XNA Framework

Supported in: 1.0
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