# Single.IsNaN(Single) Method

## Definition

Returns a value that indicates whether the specified value is not a number (NaN).

``````public:
static bool IsNaN(float f);``````
``public static bool IsNaN (float f);``
``static member IsNaN : single -> bool``
``Public Shared Function IsNaN (f As Single) As Boolean``

#### Parameters

f
Single

A single-precision floating-point number.

#### Returns

Boolean

`true` if `f` evaluates to not a number (NaN); otherwise, `false`.

## Examples

The following code example demonstrates the IsNaN method.

``````// This will return true.
if ( Single::IsNaN( 0 / zero ) )
{
Console::WriteLine( "Single::IsNan() can determine whether a value is not-a-number." );
}
``````
``````// This will return true.
if (Single.IsNaN(0 / zero))
{
Console.WriteLine("Single.IsNan() can determine whether a value is not-a-number.");
}
``````
``````' This will return true.
If Single.IsNaN(0 / zero) Then
Console.WriteLine("Single.IsNan() can determine whether a value is not-a-number.")
End If
``````

## Remarks

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.

Note

IsNaN returns `false` if a Single value is either PositiveInfinity or NegativeInfinity. To test for these values, use the IsInfinity, IsPositiveInfinity, and IsNegativeInfinity methods.