#44579 [NEW]: reading non-existing value from multidimentional array

From: alex at raintree dot ee Operating system: Windows Server 2003 PHP version: 5.2CVS-2008-03-31 (snap) PHP Bug Type: Arrays related Bug description: reading non-existing value from multidimentional array Description: ------------ Noticed serious performance issues while reading non-existing values from multi-dimensional array. Adding ISSET() check before the array read makes the script at least 3 times faster. However the main concern is that there are lots of non-optimized scripts that do not have ISSET() around multi-dimensional arrays. Reproduce code: --------------- error_reporting(0); $start = date('H:m:s'); $myArr = array('a'); $test = 'a'; // performance killer loop for($i = 0; $i < 1000000; $i++) if ($myArr[$test][$fieldName] == 5); /* optimized code if (isset($myArr[$test][$fieldName]) && $myArr[$test][$fieldName] == 5) */ $end = date('H:m:s'); echo $start . ' ' . $end; Expected result: ---------------- I expect the code with ISSET (commented out) run close to as fast as the code without ISSET. Actual result: -------------- Serious performance difference while running code that has ISSET() around multi-dimensional array read vs. code without ISSET(). -- Edit bug report at http://bugs.php.net/?id=44579&edit=1 -- Try a CVS snapshot (PHP 5.2): http://bugs.php.net/fix.php?id=44579&r=trysnapshot52 Try a CVS snapshot (PHP 5.3): http://bugs.php.net/fix.php?id=44579&r=trysnapshot53 Try a CVS snapshot (PHP 6.0): http://bugs.php.net/fix.php?id=44579&r=trysnapshot60 Fixed in CVS: http://bugs.php.net/fix.php?id=44579&r=fixedcvs Fixed in release: http://bugs.php.net/fix.php?id=44579&r=alreadyfixed Need backtrace: http://bugs.php.net/fix.php?id=44579&r=needtrace Need Reproduce Script: http://bugs.php.net/fix.php?id=44579&r=needscript Try newer version: http://bugs.php.net/fix.php?id=44579&r=oldversion Not developer issue: http://bugs.php.net/fix.php?id=44579&r=support Expected behavior: http://bugs.php.net/fix.php?id=44579&r=notwrong Not enough info: http://bugs.php.net/fix.php?id=44579&r=notenoughinfo Submitted twice: http://bugs.php.net/fix.php?id=44579&r=submittedtwice register_globals: http://bugs.php.net/fix.php?id=44579&r=globals PHP 4 support discontinued: http://bugs.php.net/fix.php?id=44579&r=php4 Daylight Savings: http://bugs.php.net/fix.php?id=44579&r=dst IIS Stability: http://bugs.php.net/fix.php?id=44579&r=isapi Install GNU Sed: http://bugs.php.net/fix.php?id=44579&r=gnused Floating point limitations: http://bugs.php.net/fix.php?id=44579&r=float No Zend Extensions: http://bugs.php.net/fix.php?id=44579&r=nozend MySQL Configuration Error: http://bugs.php.net/fix.php?id=44579&r=mysqlcfg