Double.IsInfinity Method

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

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


<SecuritySafeCriticalAttribute> _
Public Shared Function IsInfinity ( _
    d As Double _
) As Boolean
public static bool IsInfinity(
    double d


  • d
    Type: System.Double
    A double-precision floating-point number.

Return Value

Type: System.Boolean
true if d evaluates to PositiveInfinity or NegativeInfinity; otherwise, false.


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


The following example illustrates the use of IsInfinity:

' This will return "True".
outputBlock.Text &= "IsInfinity(3.0 / 0) = "
If Double.IsPositiveInfinity(3 / 0) Then
   outputBlock.Text &= "True." & vbCrLf
   outputBlock.Text &= "False." & vbCrLf
End If
// This will return "true".
outputBlock.Text += String.Format("IsInfinity(3.0 / 0) == {0}.", Double.IsInfinity(3.0 / 0) ? "true" : "false") + "\n";

Version Information


Supported in: 5, 4, 3

Silverlight for Windows Phone

Supported in: Windows Phone OS 7.1, Windows Phone OS 7.0

XNA Framework

Supported in: Xbox 360, Windows Phone OS 7.0


For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.