PRB: "Object not a Collection" Trying to Read Array Element

• Standard, Professional, and Enterprise Editions of Microsoft Visual Basic, 16-bit and 32-bit, for Windows, version 4.0

SYMPTOMS

If a public member of a class of type variant is assigned an array, you get the following error message when trying to read an element of the array by directly indexing the variant member:

   Object not a Collection.

RESOLUTION

• Dimension the object instance as being of the exact type of the class, so that it is Early Bound.

  -or-

• Index the variant member with another level of parenthesis. For example, in the "Steps to Reproduce Behavior" section of this article, use:

        Debug.Print x.arr()(0)
  

  Instead of:

        Debug.Print x.arr(0)
  

  This explicitly specifies that the variant holds an array.

STATUS

This behavior is by design.

MORE INFORMATION

Steps to Reproduce Behavior

1. Start a new project in Visual Basic. Form1 is created by default.

2. Choose Module from the Insert menu to add a new standard module (Module1)

3. Add the following code to Module1:

         Sub main()
            Dim a(2) As Integer
            a(0) = 5
   
            Dim x As Object
            Set x = New Class1
   
            x.arr = a
            Debug.Print x.arr(0)
         End Sub
   
   

4. Choose Class Module from the Insert menu to add a new class module (Class1).

5. Add the following code to Class1:

         Public arr As Variant
   

6. Press the F5 key to run the program. You will get the error message on the Debug.Print line.

Example Workaround

To work around the behavior, declare the object with a specific object type instead of Object. In Step 3 above, replace:

   Dim x As Object

   Dim x As New Class1

Keywords          : IAPVBA VB4ALL VB4WIN vbwin GnrlVb kbprg
Technology        : kbvba
Version           : WINDOWS:4.0
Platform          : WINDOWS
Issue type        : kbprb