Determines whether the specified Double is not a number (NaN).
[Visual Basic] Public Shared Function IsNaN( _ ByVal d As Double _ ) As Boolean [C#] public static bool IsNaN( double d ); [C++] public: static bool IsNaN( double d ); [JScript] public static function IsNaN( d : double ) : Boolean;
true if the number equals not a number (NaN); otherwise. false.
Note when using CompareTo or Equals, false will be returned if NaN is used. IsNaN should never be used for comparison.
(In addition see CultureInfo, NumberFormatInfo, PositiveInfinity, NegativeInfinity, and NaN.)