Double.IsNaN Method

Returns a value indicating whether the specified number evaluates to a value that is not a number (NaN).

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

public static bool IsNaN (
	double d
public static boolean IsNaN (
	double d
public static function IsNaN (
	d : double
) : boolean



A double-precision floating-point number.

Return Value

true if d evaluates to NaN; otherwise, false.

Floating-point operations return NaN to signal that that result of the operation is undefined. For example, dividing 0.0 by 0.0 results in NaN.

The following code example illustrates the use of IsNaN:

// This will return true.
if (Double.IsNaN(0 / zero)) 
    Console.WriteLine("Double.IsNan() can determine whether a value is not-a-number.");

// This will return true.
if (System.Double.IsNaN(0 / zero.doubleValue())) {
    Console.WriteLine("Double.IsNan() can determine whether" 
        + " a value is not-a-number.");

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