#41401 [Com]: Order of Operations error on divide by negative
ID: 41401
Comment by: smlerman at gmail dot com
Reported By: drlippman at yahoo dot com
Status: Open
Bug Type: Math related
Operating System: Windows, Linux
PHP Version: 4.4.7
New Comment:
<?php
echo 1 / -2 * 5; // -0.1
$a = 2;
echo 1 / -$a * 5; // -0.1
$a = -2;
echo 1 / $a * 5; // -2.5
echo 1 / -$a * 5; // 0.1
?>
Looks like a problem with the parsing of unary negation.
Previous Comments:
------------------------------------------------------------------------
[2007-05-16 18:24:03] et@php.net
This IS a bug.
http://de.php.net/operators lists unary - having higher
precedence than
the arithmetic operators, and that is the way it should be. So, this
statement should evaluate to 1/(-2)*5 and that is -2.5 and not -0.1.
------------------------------------------------------------------------
[2007-05-16 12:50:59] tony2001@php.net
Sorry, but your problem does not imply a bug in PHP itself. For a
list of more appropriate places to ask for help using PHP, please
visit http://www.php.net/support.php as this bug system
is not the
appropriate forum for asking support questions. Due to the volume
of reports we can not explain in detail here why your report is not
a bug. The support channels will be able to provide an explanation
for you.
Thank you for your interest in PHP.
------------------------------------------------------------------------
[2007-05-15 15:44:07] drlippman at yahoo dot com
Description:
------------
Left-to-right order of operations does not appear to be honored when
dividing by a negative
Reproduce code:
---------------
1/-2*5
Expected result:
----------------
-2.5
Actual result:
--------------
-.1
------------------------------------------------------------------------
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Edit this bug report at http://bugs.php.net/?id=41401&edit=1
Thread (6 messages)