IsError Function 

  • Article

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

Public Function IsError(ByVal Expression As Object) As Boolean

Parameters

  • Expression
    Required. Object expression.

Remarks

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.

Example

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

Requirements

Namespace: Microsoft.VisualBasic

Module: Information

Assembly: Visual Basic Runtime Library (in Microsoft.VisualBasic.dll)

See Also

Reference

IsArray Function (Visual Basic)
IsDate Function (Visual Basic)
IsDBNull Function
IsNothing Function
IsNumeric Function (Visual Basic)
IsReference Function
Object Data Type
TypeName Function (Visual Basic)