#41401 [Opn->Csd]: Order of Operations error on divide by negative

ID: 41401 Updated by: stas@php.net Reported By: drlippman at yahoo dot com -Status: Open +Status: Closed Bug Type: Math related Operating System: Windows, Linux PHP Version: 4.4.7 New Comment: This bug has been fixed in CVS. Snapshots of the sources are packaged every three hours; this change will be in the next snapshot. You can grab the snapshot at http://snaps.php.net/. Thank you for the report, and for helping us make PHP better. Fixed in 5/6, not in 4 though (due to objection from Derick). Previous Comments: ------------------------------------------------------------------------ [2007-05-18 00:08:51] stas@php.net Unary negation in PHP is basically 0-value (i.e. it's subtraction). The docs and the code tell difference things - the docs say unary and binary minus have different priority but in the code it's the same. ------------------------------------------------------------------------ [2007-05-17 13:02:22] smlerman at gmail dot com <?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. ------------------------------------------------------------------------ [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 ------------------------------------------------------------------------ -- Edit this bug report at http://bugs.php.net/?id=41401&edit=1