Visual Basic 3.0 Does Not Pass Parameters by Reference

ID: Q106642

The information in this article applies to:

SUMMARY

Using a Microsoft Visual Basic 3.0 application, you cannot pass parameters "by reference." Visual Basic passes all parameters "by value."

Note: This is not a limitation of OLE Automation but of Visual Basic version 3.0. Visual Basic version 4.0 supports passing parameters by reference.

WORKAROUND

The quickest way to workaround this limitation is to surround the parameter being passed with parantheses, "()". For example:

   Word.FileOpen A$

passes the parameter by reference (default). Changing the command to:

   Word.FileOpen (A$)

forces the parameter to be passed by value. This will return the evaluated value.

MORE INFORMATION

When a value is passed as an argument to a subroutine by value, a copy of the data is passed to the subroutine. If the subroutine should alter the data, the variable in the calling subroutine will go untouched since it is working with copy of the data.

If a variable is passed as an argument to a subroutine by reference, the subroutine and the calling subroutine actually share the same variable. If the subroutine should alter the variable, the variable in the calling subroutine will also be altered. This is the default mechanism Word uses for parameter passing.

KBCategory: kbmacro KBSubcategory: Additional query words: 6.0 ole automation word object word6 6.0a 6.0c 7.0 word95 winword container position visual basic vb word7

Keywords          : kbmacro
Version           : 6.0 6.0a 6.0c 7.0
Platform          : WINDOWS

Last Reviewed: July 30, 1997