#34399 [NEW]: modulus operator truncates decimal operands
| From: | me at lucasoman dot com | Date: | Tue, 06 Sep 2005 21:33:57 +0000 |
| Subject: | #34399 [NEW]: modulus operator truncates decimal operands | ||
| Groups: | php.bugs | ||
| Request: | Send a blank email to php-bugs+get-84591@lists.php.net to get a copy of this message | ||
From: me at lucasoman dot com
Operating system: Fedora Core 3
PHP version: 4.4.0
PHP Bug Type: Math related
Bug description: modulus operator truncates decimal operands
Description:
------------
This issue has been brought up before, but not in so many words.
The modulus operator (%) truncates float operands and always returns an
integer result. Some languages behave similarly, some do not. Java, for
one, correctly performs the float calculation.
I see no reason--besides ease of coding or perhaps for the sake of
efficient code--that such an arbitrary limitation would be placed on a
general mathematical operator. Some limitations, like disallowing division
by zero, are not arbitrary; these are required mathematically. However,
restricting modulus to integer operands is not mathematically logical.
You may make the suggestion that I write my own float modulus function
that performs recursive subtractions. However, if your reason for coding
mod as an integer operator is efficiency, writing <i>script</i> code to
perform this calculation--especially on large numbers--is most certainly
not more efficient.
I (humbly) request that you reconsider the way you've coded the mod
operator.
Reproduce code:
---------------
print(4.5 % 2);
Expected result:
----------------
.5
Actual result:
--------------
0
--
Edit bug report at http://bugs.php.net/?id=34399&edit=1
--
Try a CVS snapshot (php4): http://bugs.php.net/fix.php?id=34399&r=trysnapshot4
Try a CVS snapshot (php5.0): http://bugs.php.net/fix.php?id=34399&r=trysnapshot50
Try a CVS snapshot (php5.1): http://bugs.php.net/fix.php?id=34399&r=trysnapshot51
Fixed in CVS: http://bugs.php.net/fix.php?id=34399&r=fixedcvs
Fixed in release: http://bugs.php.net/fix.php?id=34399&r=alreadyfixed
Need backtrace: http://bugs.php.net/fix.php?id=34399&r=needtrace
Need Reproduce Script: http://bugs.php.net/fix.php?id=34399&r=needscript
Try newer version: http://bugs.php.net/fix.php?id=34399&r=oldversion
Not developer issue: http://bugs.php.net/fix.php?id=34399&r=support
Expected behavior: http://bugs.php.net/fix.php?id=34399&r=notwrong
Not enough info: http://bugs.php.net/fix.php?id=34399&r=notenoughinfo
Submitted twice: http://bugs.php.net/fix.php?id=34399&r=submittedtwice
register_globals: http://bugs.php.net/fix.php?id=34399&r=globals
PHP 3 support discontinued: http://bugs.php.net/fix.php?id=34399&r=php3
Daylight Savings: http://bugs.php.net/fix.php?id=34399&r=dst
IIS Stability: http://bugs.php.net/fix.php?id=34399&r=isapi
Install GNU Sed: http://bugs.php.net/fix.php?id=34399&r=gnused
Floating point limitations: http://bugs.php.net/fix.php?id=34399&r=float
No Zend Extensions: http://bugs.php.net/fix.php?id=34399&r=nozend
MySQL Configuration Error: http://bugs.php.net/fix.php?id=34399&r=mysqlcfg