VB6 Subscript out of range - ARRAY

[jjsomer]

I call a third party function that returns an array. I dimension the array to zero elements before calling the function. However, occasionally the function returns an array with no upper or lower bound (similar to creating a modular level dynamic array). How can I check for this situation without using an error handling routine? I currently check the array's UBound, but on this occurrence a 'subscript out of range' occurs. Code snippet shown below:

    'Reset the sensor id byte array.
    ReDim bytSensorID(0) As Byte
    
    'Determine if the device has been initialized.
    If mboolInitialized Then
        'Device has been initialized.
        '   Request the sensor id information.
        bytSensorID = mobjSATTester.getSensorIDByteArray()
        'This statement errors on occasion with subscript out of range
        lngUpperBound = ubound(bytSensorID)

[Hack]

How about If UBound(bytSensorID) > 0 Then

[jjsomer]

Try the code below. It will generate a 'subscript out of range' error. The array hasn't been dimensioned. How can I check if an array hasn't been dimensioned?

Option Explicit
Private mstrArray() As String

Private Sub Command1_Click()

    If UBound(mstrArray) > 0 Then
        MsgBox "here"
    End If
    
End Sub

[Ellis Dee]

Use this:

' Returns 0 for unintialized array, -1 for non-array
Public Function ArrayDimensions(pvarArray As Variant) As Long
    Dim lngTemp As Long
    Dim i As Long
    
    On Error Resume Next
    Do
        i = i + 1
        lngTemp = UBound(pvarArray, i)
        Select Case Err.Number
            Case 13: ArrayDimensions = -1
            Case 9: ArrayDimensions = i - 1
        End Select
    Loop Until Err.Number
End Function

[jjsomer]

Yep. I like it. Didn't know if it was possible without using vb error handling. I've tried IsArray, IsNull, IsEmpty. Seems weird that there isn't a canned function for this in VB6.

Use this:

' Returns 0 for unintialized array, -1 for non-array
Public Function ArrayDimensions(pvarArray As Variant) As Long
    Dim lngTemp As Long
    Dim i As Long
    
    On Error Resume Next
    Do
        i = i + 1
        lngTemp = UBound(pvarArray, i)
        Select Case Err.Number
            Case 13: ArrayDimensions = -1
            Case 9: ArrayDimensions = i - 1
        End Select
    Loop Until Err.Number
End Function

[Ellis Dee]

If you really want to avoid error handling, see this thread. As much as I hate intentionally raising errors, this is one instance where IMO it is preferable.