DOCUMENT:Q153200  15-DEC-1999  [foxpro]
TITLE   :How To Determine Whether a Number is Prime
PRODUCT :Microsoft FoxPro
PROD/VER:MACINTOSH:2.5b,2.5c,2.6a; MS-DOS:2.0,2.5,2.5a,2.5b,2.6,2.6a; UNIX:2.6; WINDOWS:3.0,3.0b
OPER/SYS:
KEYWORDS:

======================================================================
-------------------------------------------------------------------------------
The information in this article applies to:

 - Microsoft Visual FoxPro for Windows, versions 3.0, 3.0b 
 - Microsoft FoxPro for Macintosh, versions 2.5b, 2.5c, 2.6a 
 - Microsoft FoxPro for MS-DOS, versions 2.0, 2.5, 2.5a, 2.5b, 2.6, 2.6a 
 - Microsoft FoxPro for UNIX, version 2.6 
 - Microsoft Visual FoxPro for Macintosh, Professional Edition, version 3.0 
-------------------------------------------------------------------------------

SUMMARY
=======

There is no single function in FoxPro or Visual FoxPro that determines whether a
number is prime. This article describes how to use a program that allows you to
enter a positive number and then reports if that number is prime.

MORE INFORMATION
================

A prime number is a number divisible only by one and itself. The following
program uses the MOD()and ABS() functions along with a For...Next loop to check
if a number is prime:

      CLEAR
      SET TALK OFF
      x=0
      @ 1,10 SAY "Please enter a positive integer"  GET x
      READ
      x=ABS(x)
      FOR i=2 to x-1
         IF MOD(x,i)=0
             @2,10 SAY  "The number "+ ALLTRIM(STR(x))+ " is not prime."
             RETURN
         ENDIF
      ENDFOR
      @ 2,10 SAY "The number "+ ALLTRIM(STR(x))+ " is prime."
      SET TALK ON

While this program uses the READ statement for backward compatibility with FoxPro
2.x versions, the basic algorithm may be used in a form within Visual FoxPro.

Additional query words: VFoxWin VFoxMac

======================================================================
Keywords          :  
Technology        : kbHWMAC kbOSMAC kbVFPsearch kbAudDeveloper kbFoxproSearch kbZNotKeyword3 kbFoxPro250bMac kbFoxPro260aMac kbFoxPro250cMac kbFoxPro200DOS kbFoxPro250DOS kbFoxPro250aDOS kbFoxPro250bDOS kbFoxPro260DOS kbFoxPro260aDOS kbFoxPro260UNIX kbVFP300Mac kbVFP300 kbVFP300b
Version           : MACINTOSH:2.5b,2.5c,2.6a; MS-DOS:2.0,2.5,2.5a,2.5b,2.6,2.6a; UNIX:2.6; WINDOWS:3.0,3.0b; :3.0

=============================================================================

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 1999.