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Double::IsNaN Method (Double)

.NET Framework (current version)
 

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

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

C#
C++
F#
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Copy 
public:
static bool IsNaN(
	double d
)

Parameters

d
Type: System::Double

A double-precision floating-point number.

Return Value

Type: System::Boolean

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.

System_CAPS_noteNote

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

The following code example illustrates the use of IsNaN:

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

Universal Windows Platform
Available since 8
.NET Framework
Available since 1.1
Portable Class Library
Supported in: portable .NET platforms
Silverlight
Available since 2.0
Windows Phone Silverlight
Available since 7.0
Windows Phone
Available since 8.1
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