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# Double.IsInfinity Method

.NET Framework 1.1

Returns a value indicating whether the specified number evaluates to negative or positive infinity

```[Visual Basic]
Public Shared Function IsInfinity( _
ByVal d As Double _
) As Boolean
[C#]
public static bool IsInfinity(
double d
);
[C++]
public: static bool IsInfinity(
double d
);
[JScript]
public static function IsInfinity(
d : double
) : Boolean;```

#### Parameters

d
A double-precision floating point number.

#### Return Value

true if d evaluates to PositiveInfinity or NegativeInfinity; otherwise, false.

#### Remarks

Floating-point operations return PositiveInfinity or NegativeInfinity to signal an overflow condition.

#### Example

[Visual Basic, C#, C++] The following code sample illustrates the use of IsInfinity:

```[Visual Basic]
' This will return "True".
Console.Write("IsInfinity(3.0 / 0) = ")
If Double.IsPositiveInfinity(3 / 0) Then
Console.WriteLine("True.")
Else
Console.WriteLine("False.")
End If

[C#]
// This will return "true".
Console.WriteLine("IsInfinity(3.0 / 0) == {0}.", Double.IsInfinity(3.0 / 0) ? "true" : "false");

[C++]
// This will return S"true".
Console::WriteLine(S"IsInfinity(3.0 / 0) == {0}.", Double::IsInfinity(3.0 / zero) ? S"true" : S"false");
```

[JScript] No example is available for JScript. To view a Visual Basic, C#, or C++ example, click the Language Filter button in the upper-left corner of the page.

#### Requirements

Platforms: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family, .NET Compact Framework, Common Language Infrastructure (CLI) Standard