Double.IsNaN(Double) Method

public:
 static bool IsNaN(double d);

public:
 static bool IsNaN(double d) = System::Numerics::INumberBase<double>::IsNaN;

public static bool IsNaN(double d);

static member IsNaN : double -> bool

Public Shared Function IsNaN (d As Double) As Boolean

true if d evaluates to NaN; otherwise, false.

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

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

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

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

• NaN