Req #74551 [NEW]: json_encode() assumes that one dimensional array is an object

From: jon dot ronnenberg at gmail dot com Operating system: Linux Ubuntu Mate 16.04 PHP version: 7.0.18 Package: JSON related Bug Type: Feature/Change Request Bug description:json_encode() assumes that one dimensional array is an object Description: ------------ <?php ## json_encode() assumes that one dimensional array is an object ## # Note, To run the entire bug report in php, just copy/paste the entire # content into a php file and run php your_file.ph # Unsetting an element will also remove the keys. # json_encode() will now assume that this is an object, # and will encode it as such. # ref: http:#php.net/manual/en/function.json-encode.php#94157 # Note, that JSON_PRETTY_PRINT has no effect on the behavior # Example: $array = [0,1,2]; print_r(json_encode($array, JSON_PRETTY_PRINT)); unset($array[1]); print_r(json_encode($array, JSON_PRETTY_PRINT)); # The real issue and bug introducing confusing comes with array_filter. # Example: $array = [0,1,2,3,4,5,6,7,8,9,10]; $odds = function($d) { return $d % 2; }; print_r(json_encode(array_filter($array, $odds), JSON_PRETTY_PRINT)); # The work-around is to always use array_values, when you know that you will # serialize a one dimensional array. # Example: $array = [0,1,2,3,4,5,6,7,8,9,10]; $odds = function($d) { return $d % 2; }; print_r(json_encode(array_values(array_filter($array, $odds)), JSON_PRETTY_PRINT)); # Since the data manipulation is often handled in other layers than the # serialization, this can lead to subtle and hard to trace bugs. # Often only found when deployed since this does not happen in all cases, # as shown below. # Example: $array = [0,1,2,3,4,5,6,7,8,9,10]; $below2 = function($d) { return $d < 2; }; print_r(json_encode(array_filter($array, $below2), JSON_PRETTY_PRINT)); # Changing the behavior of array_filter might introduce breaking change # while changing how json_encode handles one dimensional arrays should # not. # I'm not filing this as a bug, since it has been reported seven years # ago, but it definitely tangents a bug. # Seven years ago, simoncpu, reported this behavior in the User Contributed Notes, # http://php.net/manual/en/function.json-encode.php#94157 # Another bug report touches on the subject: # https://bugs.php.net/bug.php?id=45162 # But it's hard to distill what the author expect or believe to be wrong # with the behavior. # This report tries to be concise and has nothing to do with associative arrays. ?> Test script: --------------- # The two print_r statements should output the same: $array = [0,1,2]; print_r(json_encode($array, JSON_PRETTY_PRINT)); unset($array[1]); print_r(json_encode($array, JSON_PRETTY_PRINT Expected result: ---------------- [ 0, 1, 2 ][ 0, 1, 2 ] Actual result: -------------- [ 0, 1, 2 ]{ "0": 0, "2": 2 } -- Edit bug report at https://bugs.php.net/bug.php?id=74551&edit=1 -- Try a snapshot (PHP 5.4): https://bugs.php.net/fix.php?id=74551&r=trysnapshot54 Try a snapshot (PHP 5.5): https://bugs.php.net/fix.php?id=74551&r=trysnapshot55 Try a snapshot (trunk): https://bugs.php.net/fix.php?id=74551&r=trysnapshottrunk Fixed in SVN: https://bugs.php.net/fix.php?id=74551&r=fixed Fixed in release: https://bugs.php.net/fix.php?id=74551&r=alreadyfixed Need backtrace: https://bugs.php.net/fix.php?id=74551&r=needtrace Need Reproduce Script: https://bugs.php.net/fix.php?id=74551&r=needscript Try newer version: https://bugs.php.net/fix.php?id=74551&r=oldversion Not developer issue: https://bugs.php.net/fix.php?id=74551&r=support Expected behavior: https://bugs.php.net/fix.php?id=74551&r=notwrong Not enough info: https://bugs.php.net/fix.php?id=74551&r=notenoughinfo Submitted twice: https://bugs.php.net/fix.php?id=74551&r=submittedtwice register_globals: https://bugs.php.net/fix.php?id=74551&r=globals PHP 4 support discontinued: https://bugs.php.net/fix.php?id=74551&r=php4 Daylight Savings: https://bugs.php.net/fix.php?id=74551&r=dst IIS Stability: https://bugs.php.net/fix.php?id=74551&r=isapi Install GNU Sed: https://bugs.php.net/fix.php?id=74551&r=gnused Floating point limitations: https://bugs.php.net/fix.php?id=74551&r=float No Zend Extensions: https://bugs.php.net/fix.php?id=74551&r=nozend MySQL Configuration Error: https://bugs.php.net/fix.php?id=74551&r=mysqlcfg