Q40890: BC "Variable Name Not Unique" on SUB with Period in Name

Article: Q40890
Product(s): See article
Version(s): 4.00 4.00b 4.50
Operating System(s): MS-DOS
Keyword(s): ENDUSER | SR# S890123-207 B_BasicCom | mspl13_basic
Last Modified: 14-DEC-1989

If a BASIC SUBprogram name contains a period (that is, a dot), then
any variables that have the same name as the portion of the SUBprogram
name that is left of the period produce a "Variable name not unique"
error message from BC.EXE at compile time. The program does not
produce the error inside the QB.EXE editor environment.

This information applies to Microsoft QuickBASIC Versions 4.00, 4.00b,
and 4.50 and Microsoft BASIC Compiler Versions 6.00 and 6.00b for
MS-DOS and MS OS/2.

This behavior does not occur in Microsoft BASIC PDS Version 7.00.
BASIC PDS Version 7.00 will successfully compile a program under the
above conditions.

The sample program below runs inside the QuickBASIC environment.
However, when compiled using BC.EXE, a "Variable name not unique"
error message is produced.

It is recommended that variable and subprogram/function names contain
no periods. Periods are now used by BASIC in specifying individual
elements of a user-defined type variable. To eliminate the problem in
the program below, remove the period from the SUBprogram name.

The following is a code example:

DECLARE SUB Test.one ()
COMMON SHARED Test AS SINGLE
Test = 4
CALL Test.one
END

SUB Test.one
  PRINT "in Test.one"
END SUB

THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY.

Copyright Microsoft Corporation 1986-2002.