Q42588: "Variable Required" Versus "Duplicate Definition" Error

Article: Q42588
Product(s): See article
Version(s): 4.00 4.00b 4.50
Operating System(s): MS-DOS
Keyword(s): ENDUSER | SR# S890227-97 B_BasicCom | mspl13_basic
Last Modified: 16-DEC-1989

This information applies to QuickBASIC Versions 4.00, 4.00b, and 4.50
for MS-DOS, to Microsoft BASIC Compiler Versions 6.00 and 6.00b for
MS-DOS and MS OS/2, and to Microsoft BASIC PDS Version 7.00 for MS-DOS
and MS OS/2.

When a program attempts to define a variable and a function to have
the same name, an error occurs. Normally, this error is "DUPLICATE
DEFINITION." However, if the variable is first used in a FOR...NEXT
statement, then the error message issued from QB.EXE (or QBX.EXE under
the BASIC PDS 7.00) is "Variable Required", but from BC.EXE the two
error messages "Variable Required" and "NEXT WITHOUT FOR" are
generated.

The following Code will generate a "Variable Required" error in
QB.EXE / QBX.EXE:

DECLARE FUNCTION bit% ()

FOR bit% = 0 TO 7
NEXT

FUNCTION bit%
  bit% = 5
END FUNCTION

Under QuickBASIC 4.50, pressing the HELP button for the "Variable
Required" error box misleadingly gives the following run-time error
explanation instead of the compile-time explanation:

   "A GET or PUT statement must specify a variable when operating
    on a file opened in binary mode. ERR code: #40.

The compile-time meaning of "Variable Required" explained in the
"Microsoft QuickBASIC: Programming in BASIC" manual for Version 4.50
is more accurate.