Q129836: PRB: Object Variable Not Set Error If Object Not Instantiated

Article: Q129836
Product(s): Microsoft Visual Basic for Windows
Version(s): 
Operating System(s): 
Keyword(s): 
Last Modified: 11-JAN-2001

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The information in this article applies to:

- Microsoft Visual Basic Standard Edition, 32-bit, for Windows, version 4.0 
- Microsoft Visual Basic Professional Edition, 16-bit, for Windows, version 4.0 
- Microsoft Visual Basic Professional Edition, 32-bit, for Windows, version 4.0 
- Microsoft Visual Basic Enterprise Edition, 16-bit, for Windows, version 4.0 
- Microsoft Visual Basic Enterprise Edition, 32-bit, for Windows, version 4.0 
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SYMPTOMS
========

Referencing an object that has not been instantiated results in this error:

  "Object variable or With block variable not Set"
  (Err = 91)

CAUSE
=====

If you declare an object as in this example:

     Dim MyForm as Form1

you have allocated a reference to the object (similar to a pointer in the C
programming language), but you have not allocated or instantiated the object
itself.

Therefore, when the object is referenced in code as in this example:

     MyForm.Print "Hello World!"

the error message "Object variable or With block not Set" is generated.

RESOLUTION
==========

The following three code examples demonstrate how to declare and use an object
variable (MyForm in this case) correctly:

Code Sample One
---------------

  Dim MyForm as Form1
  Set MyForm = New Form1
  ' Where the object type is the same as the object type used in the
  ' declaration.
  MyForm.Print "Hello World!"

Code Sample Two
---------------

  Dim MyForm as New Form1
  MyForm.Print "Hello World!"

Code Sample Three
-----------------

  Dim MyForm as Form1
  Dim MyForm1 as New Form1
  Set MyForm= MyForm1
  MyForm.Print "Hello World!"

Additional query words: 4.00 vb4win vb4all

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Keywords          :  
Technology        : kbVBSearch kbAudDeveloper kbVB400Search kbVB400 kbVB16bitSearch
Issue type        : kbprb

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