XL97: Error When Passing an Array Value Between Macros

• Microsoft Excel 97 for Windows

SYMPTOMS

When you run a Visual Basic for Applications macro in Microsoft Excel 97, you may receive the following error message:

   Run-time error '10':
   This array is fixed or temporarily locked.

CAUSE

This behavior will occur if the following conditions are all true:

• You create two macros, where one macro passes a variable to the other macro.

      -and-
  

• The variable that is passed to the other macro is an element of an array.

      -and-
  

• The second macro accepts the variable by reference, not by value.

      -and-
  

• The second macro uses the ReDim method to redimension the array.

WORKAROUND

Microsoft provides examples of Visual Basic for Applications procedures for illustration only, without warranty either expressed or implied, including, but not limited to the implied warranties of merchantability and/or fitness for a particular purpose. The Visual Basic procedures in this article are provided 'as is' and Microsoft does not guarantee that they can be used in all situations. While Microsoft support engineers can help explain the functionality of a particular macro, they will not modify these examples to provide added functionality, nor will they help you construct macros to meet your specific needs. If you have limited programming experience, you may want to consult one of the Microsoft Solution Providers. Solution Providers offer a wide range of fee-based services, including creating custom macros. For more information about Microsoft Solution Providers, call Microsoft Customer Information Service at (800) 426-9400.

The following workarounds assume that you created a Visual Basic module with the following code:

   Dim MyArray() As Integer

   Sub Macro1()     'The first macro
       ReDim MyArray(10)
       Macro2 MyArray(1)
   End Sub

   Sub Macro2(X)    'The second macro
       ReDim MyArray(20)
   End Sub

NOTE: If you run Macro1, you receive the error message.

To prevent the problem from occurring, use either of the following methods.

Method 1:

In the second macro, use the keyword ByVal to force the macro to refer to the element in the array by value, not by reference. For example, change the second macro to the following:

   Sub Macro2(ByVal X)    'Note the "ByVal" keyword.
       ReDim MyArray(20)
   End Sub

Use an intermediate variable to pass the value from one macro to the other. For example, change the first macro to the following:

   Sub Macro1()
       ReDim MyArray(10)
       Z = MyArray(1)     'Set the intermediate variable value.
       Macro2 Z           'Run the second macro and pass the value.
   End Sub

STATUS

This behavior is by design of Microsoft Excel 97.

NOTE: This behavior is a change from earlier versions of Microsoft Excel.

MORE INFORMATION

When you pass a variable from one macro to another macro in Microsoft Excel, the actual value of the variable is not passed between macros. Instead, a reference to the value's location in memory is passed; this is called passing a value by reference. You can also pass a value by value by using the keyword ByVal.

If you pass an element of an array from one macro to another by reference, and then attempt to redimension the array by using the ReDim method, you receive the error message in this article. This behavior occurs because the array's size is locked when a macro refers to it. Only when the reference is released can the array be redimensioned.

Note that this limitation does not apply to earlier versions of Microsoft Excel.