Article: Q38279
Product(s): See article
Version(s): 4.00 4.00b 4.50
Operating System(s): MS-DOS
Keyword(s): ENDUSER | B_BasicCom buglist4.00 buglist4.00b fixlist4.50 | mspl13_basic
Last Modified: 13-MAR-1990
Code Example 1 below shows a case where you must compile a QuickBASIC
Version 4.00 or 4.00b program that uses LONG-integer arrays with the
/d (debug) option, or else restructure the program as shown in Example
2. Otherwise, the result of a division with a LONG-integer array may
incorrectly result in zero.
Microsoft has confirmed this to be a problem in QuickBASIC Versions
4.00 and 4.00b, and in Microsoft BASIC Compiler Versions 6.00 and
6.00b for MS-DOS and MS OS/2 (buglist6.00, buglist6.00b). This problem
was corrected in QuickBASIC Version 4.50 and in Microsoft BASIC
Professional Development System (PDS) Version 7.00 for MS-DOS and MS
OS/2 (fixlist7.00).
When Code Example 1 below is compiled with BC.EXE in QuickBASIC
Version 4.00 or 4.00b, (in Microsoft BASIC Compiler Versions 6.00 and
6.00b for MS-DOS and OS/2, the debug (/d) option is required). If you
compile without using the /d option, the code produces the following
printout:
20000 0 0 0
20000 0 0 0
20000 0 0 0
Code Example 1 displays the following correct results when executed
within the QB.EXE editor:
20000 20000 0 0
20000 20000 20000 0
20000 20000 20000 20000
If you use a temporary variable to hold the value of Ddiv(ival) and
then divide by the temporary variable, the correct results are
generated (see Example 2).
[Note that QuickBASIC versions earlier than 4.00 and BASIC compiler
versions earlier than 6.00 do not support long integers.]
The following are code examples:
Example 1
---------
' Requires BC.EXE debug (/d) option in Versions 4.00 and 4.00b.
' OK in BC.EXE Version 4.50 with or without /d (debug) option.
DEFINT I, L: DEFLNG N: DEFDBL D
DIM NVal(3), NNum(3), Ddiv(5)
Ddiv(2) = 5
Ival = 2
FOR i = 0 TO 2
NNum(i) = 100000
NVal(i) = NNum(i) / Ddiv(Ival)
PRINT NVal(i); NVal(0); NVal(1); NVal(2)
NEXT
Example 2
---------
' This works with or without /d (debug) option in Versions 4.00,
' 4.00b, and 4.50.
DEFINT I, L: DEFLNG N: DEFDBL D
DIM NVal(3), NNum(3), Ddiv(5)
Ddiv(2) = 5
Ival = 2
FOR i = 0 TO 2
NNum(i) = 100000
DTemp = Ddiv(Ival)
NVal(i) = NNum(i) / DTemp
PRINT NVal(i); NVal(0); NVal(1); NVal(2)
NEXT