BASIC &num Constant Defaults to &Onum (Octal), Not &Hnum (Hex) (59403)


The information in this article applies to:

  • Microsoft QuickBASIC Compiler for the Apple Macintosh 1.0
  • Microsoft BASIC Compiler
  • Microsoft BASIC Interpreter for Apple Macintosh 1.0
  • Microsoft BASIC Interpreter for Apple Macintosh 1.01
  • Microsoft BASIC Interpreter for Apple Macintosh 2.0
  • Microsoft BASIC Interpreter for Apple Macintosh 2.1
  • Microsoft BASIC Interpreter for Apple Macintosh 3.0
  • Microsoft QuickBASIC 1.0
  • Microsoft QuickBASIC 1.01
  • Microsoft QuickBASIC 1.02
  • Microsoft QuickBASIC 2.0
  • Microsoft QuickBASIC 2.01
  • Microsoft QuickBASIC 3.0
  • Microsoft QuickBASIC 4.0
  • Microsoft QuickBASIC 4.0b
  • Microsoft QuickBASIC 4.5
  • Microsoft BASIC Compiler for MS-DOS and OS/2 6.0
  • Microsoft BASIC Compiler for MS-DOS and OS/2 6.0b
  • Microsoft Basic Professional Development System (PDS) for MS-DOS and MS OS/2 7.0
  • Microsoft GW-BASIC 3.2
  • Microsoft GW-BASIC 3.22
  • Microsoft GW-BASIC 3.23
This article was previously published under Q59403

SUMMARY

In all versions of Microsoft BASIC products, the base for a literal constant that begins with an ampersand (&) alone (not &H, &h, &O, or &o) defaults to octal (equivalent to &O or &o). Thus, if you type a literal such as the following

&700

then all versions of Microsoft BASIC will assume that this is an octal literal equivalent to &o700.

In fact, many Microsoft BASIC Interpreters (such as GW-BASIC Versions 3.20 and later for MS-DOS; QuickBASIC Versions 4.00 and later for MS-DOS; Microsoft BASIC Interpreter Versions 2.00, 2.10, and 3.00 for the Apple Macintosh; and QuickBASIC Version 1.00 for the Apple Macintosh) actually alter the literal to &o700 to show they are making this assumption.

The octal default for a literal constant that begins with a lone ampersand (&) occurs in the following products:

  1. Microsoft QuickBASIC Version 1.00 for the Apple Macintosh
  2. Microsoft BASIC Compiler Version 1.00 for the Apple Macintosh
  3. Microsoft BASIC Interpreter Versions 1.00, 1.01, 2.00, 2.10, and 3.00 for the Apple Macintosh
  4. Microsoft QuickBASIC Versions 1.00, 1.01, 1.02, 2.00, 2.01, 3.00, 4.00, 4.00b, 4.50 for MS-DOS
  5. Microsoft BASIC Compiler Versions 5.35 and 5.36 for MS-DOS
  6. Microsoft BASIC Compiler Versions 6.00 and 6.00b for MS OS/2 and MS-DOS
  7. Microsoft BASIC Professional Development System (PDS) Version 7.00 for MS-DOS and MS OS/2
  8. Microsoft GW-BASIC Interpreter Versions 3.20, 3.22, and 3.23

MORE INFORMATION

To demonstrate this feature of BASIC, enter the following code into the environment one of the BASIC interpreters, such as GW-BASIC or Microsoft QuickBASIC: 

   40 CLS
   50 PRINT &700    ' This will print out as 448 (decimal value)
   55 PRINT &o700   ' This will print out as 448 (decimal value)
   60 PRINT &H700   ' This will print out as 1792 (decimal value)
   70 END


In many Microsoft BASIC interpreters (such as GW-BASIC 3.20 or later for MS-DOS; QuickBASIC 4.00 and later for MS-DOS; BASIC interpreter 2.00, 2.10, and 3.00 for the Apple Macintosh; or QuickBASIC 1.00 for the Apple Macintosh), the editor automatically changes lines 50 and 55 to the following: 

   50 PRINT &O700
   55 PRINT &O700


If you want a hexadecimal number, the & (ampersand sign) must be followed with H, as in line 60 above.
Modification Type:MinorLast Reviewed:8/16/2005
Keywords:KB59403
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