VBA: Don't go into loop when array is empty - vba

Question

I have a loop that can look like this:
For Each article In artAll
Next
or like this:
For i = 0 To Ubound(artAll)
Next
When the array length is 0, I get an error message. What is a good way to skip the loop when the array is empty? I suspect that I should use
On Error Goto
but I need help finalizing a solution.

Answer 1

If Len(Join(artAll, "")) = 0 Then
'your for loops here
Should work

Answer 2

I use this function to test for empty arrays:
Public Function isArrayEmpty(parArray As Variant) As Boolean
'Returns false if not an array or dynamic array that has not been initialised (ReDim) or has been erased (Erase)
If IsArray(parArray) = False Then isArrayEmpty = True
On Error Resume Next
If UBound(parArray) < LBound(parArray) Then isArrayEmpty = True: Exit Function Else: isArrayEmpty = False
End Function
Then in your main code:
If isArrayEmpty(yourArray) Then
'do something - typically:
MsgBox "Empty Array"
Exit Function
End If
For i = LBound(yourArray,1) To UBound(yourArray,1)
'do something
Next i

Answer 3

I like the solution given by #Dan but thought I would throw out there how I would normally handle an undimensionalized array:
Dim lngUboundTest As Long
lngUboundTest = -1
On Error Resume Next
lngUboundTest = UBound(artAll)
On Error GoTo 0
If lngUboundTest >= 0 Then
'Your loop...

Answer 4

This is an old question, but I found this solution to the problem, and it could be helpful to others:
If (Not myArray) = True Then
'Undimensionalized array. Respond as needed.
Else
'Array isn't empty, you can run your loop.
End If
It helped my out in a recent project, and found it to be very handy.

Answer 5

I found this thread looking for a solution to a problem where looping through a multidimensional array would fail if a dimensioned element was empty. I created the array by looping through a source that could have up to 6 datasets. Then after processing I would repeat this 19 more times.
Dim varDeskData As Variant
Dim varDesk As Variant
ReDim varDesk(1 To 6)
For y = 1 To 6
ReDim varDeskData(1 To 4)
varDeskData(1) = "nifty integer from source(y)"
varDeskData(2) = "nifty string from source(y)"
varDeskData(3) = "another nifty string from source(y)"
varDeskData(4) = "another nifty string from source(y)"
varDesk(y) = varDeskData
Next y
When I ran the following, I would get the first three processed but then it would fail on the fourth, because I had only loaded three into the parent array:
For y = 1 To 6
If varDesk(y)(1) > 0 Then
... do nifty stuff ...
End If
End If
Using the IsEmpty procedure on the top level elements of the parent array fixed this:
For y = 1 To 6
If IsEmpty(varDesk(y)) = False Then
If varDesk(y)(1) > 0 Then
... do nifty stuff ...
End If
End If
End If