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Q48725: "Illegal Number" Using -2147483648& in Long Integer Notation

Article: Q48725
Product(s): See article
Version(s): 4.00 4.00b 4.50
Operating System(s): MS-DOS
Keyword(s): ENDUSER | SR# S890824-44 B_BasicCom | mspl13_basic
Last Modified: 20-DEC-1989

BC.EXE, QB.EXE, and QBX.EXE do not allow the "&" character on the end
of the smallest (negative) constant allowed for a long integer,
-2147483648. To enter the smallest long integer constant in your
source code, you must use either (-2147483647& - 1&) or -2147483648#.

This information applies to Microsoft 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.

The BC.EXE compiler reports an "Illegal type character in numeric
constant" error, and the QB.EXE and QBX.EXE editors report an "Illegal
number" error for the following statement:

   A& = -2147483648&

The error may have surprised you since -2147483648& is within the
allowed range for long integers (-2147483648& to +2147483647&).

However, this is not a software problem. Both the BASIC compiler and
the QB and QBX interpreters parse -2147483648& as follows:

   - (2147483648&)

In other words, "take a large long integer and negate it." This means
that the number is first parsed as a positive long integer and then it
is negated before it is assigned to the number. However, the largest
positive long integer is 2147483647 (one fewer than the largest
negative number), making 2147483648& an illegal number, and therefore,
causing an error.

You must use one of the following instead:

   A& = (-2147483647& - 1&)
or
   A& = -2147483648#

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