#31285 [NEW]: something about operator precedence

From: geometer at ua dot fm Operating system: * PHP version: Irrelevant PHP Bug Type: Math related Bug description: something about operator precedence Description: ------------ hello it's not a bug, but an UNREASONABLE peculiarity of PHP (all versions). the peculiarity may be a reason of "strange" behavior of a script and errors may take a lot of time for their fixing. i say about precedence of some operators. let's take a look on precedence of bitwise operator "&" and comparison one "==". let me need to find out is number of the lowest significant bits in $x is less then 8 or not. as it can be done in other programming languages, i use the following construction: if ($x&0x7f==$x) {ok} else {not ok} if you try to use such a construction in a script you would be amazed, because $x&0x7f==$x IS TRUE IF AND ONLY IF $x IS EQUAL TO 0x7f! if you try to use 0x7f&$x==$x instead of original condition, you would be amazed twice, because 0x7f&$x==$x IS ALWAYS TRUE. and what the reason of this tricks? the reason is the precedence of "&" is LOWER than one of "==". so, i HAVE to write ($x&0x7f)==$x or (0x7f&$x)==$x, because taking into account the precedence one obtains: $x&0x7f==$x <=> $x&(0x7f==$x) 0x7f&$x==$x <=> 0x7f&($x==$x) such behavior is not common in programming and in mathematics. and even if i aware about the precedence, i can make a mistake "on the fly" in expression (do you like to print additional parenthesis? ;)). so, what's the reason of such particuliarly in PHP? may be it needs to be removed from the following releases? Reproduce code: --------------- <? $x = 0x76; echo $x&0x7f==$x; echo "\n"; echo 0x7f&$x==$x; ?> Expected result: ---------------- 1 1 Actual result: -------------- 0 1 -- Edit bug report at http://bugs.php.net/?id=31285&edit=1 -- Try a CVS snapshot (php4): http://bugs.php.net/fix.php?id=31285&r=trysnapshot4 Try a CVS snapshot (php5.0): http://bugs.php.net/fix.php?id=31285&r=trysnapshot50 Try a CVS snapshot (php5.1): http://bugs.php.net/fix.php?id=31285&r=trysnapshot51 Fixed in CVS: http://bugs.php.net/fix.php?id=31285&r=fixedcvs Fixed in release: http://bugs.php.net/fix.php?id=31285&r=alreadyfixed Need backtrace: http://bugs.php.net/fix.php?id=31285&r=needtrace Need Reproduce Script: http://bugs.php.net/fix.php?id=31285&r=needscript Try newer version: http://bugs.php.net/fix.php?id=31285&r=oldversion Not developer issue: http://bugs.php.net/fix.php?id=31285&r=support Expected behavior: http://bugs.php.net/fix.php?id=31285&r=notwrong Not enough info: http://bugs.php.net/fix.php?id=31285&r=notenoughinfo Submitted twice: http://bugs.php.net/fix.php?id=31285&r=submittedtwice register_globals: http://bugs.php.net/fix.php?id=31285&r=globals PHP 3 support discontinued: http://bugs.php.net/fix.php?id=31285&r=php3 Daylight Savings: http://bugs.php.net/fix.php?id=31285&r=dst IIS Stability: http://bugs.php.net/fix.php?id=31285&r=isapi Install GNU Sed: http://bugs.php.net/fix.php?id=31285&r=gnused Floating point limitations: http://bugs.php.net/fix.php?id=31285&r=float No Zend Extensions: http://bugs.php.net/fix.php?id=31285&r=nozend MySQL Configuration Error: http://bugs.php.net/fix.php?id=31285&r=mysqlcfg