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IsError Method

Information.IsError Method

Returns a Boolean value indicating whether an expression is an exception type.

Namespace:  Microsoft.VisualBasic
Assembly:  Microsoft.VisualBasic (in Microsoft.VisualBasic.dll)

public static bool IsError(
	Object Expression


Type: System.Object
Required. Object expression.

Return Value

Type: System.Boolean
Returns a Boolean value indicating whether an expression is an exception type.

IsError returns True if the expression represents an Object variable that derives from the Exception class in the System namespace.

An exception that derives from System.Exception can be caught with the Try...Catch...Finally statements.

The following example uses the IsError function to check if an expression represents a system exception.

Sub demonstrateIsError(ByVal firstArg As Integer)
    Dim returnVal As New Object
    Dim badArg As String = "Bad argument value"
    Dim errorCheck As Boolean
    If firstArg > 10000 Then
        returnVal = New System.ArgumentOutOfRangeException(badArg)
    End If
    errorCheck = IsError(returnVal)
End Sub

.NET Framework

Supported in: 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Community Additions

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