Bug #79850 [Opn->Csd]: array_walk / array_filter incorrectly warn variables should be passed by ref

Edit report at https://bugs.php.net/bug.php?id=79850&edit=1 ID: 79850 Updated by: sjon@php.net Reported by: sjon@php.net Summary: array_walk / array_filter incorrectly warn variables should be passed by ref -Status: Open +Status: Closed Type: Bug Package: Arrays related Operating System: archLinux PHP Version: 8.0.0alpha2 -Assigned To: +Assigned To: sjon Block user comment: N Private report: N New Comment: For https://3v4l.org/ZCgRe, instead of array_shift/array_pop, reset/end should have been used as they return the same value but don't modify the original value. This message will probably confuse more users Previous Comments: ------------------------------------------------------------------------ [2020-07-14 12:42:41] sjon@php.net Aha, so this fix would be for the user to write ``` $newIds = array_filter($ids, function($n) { return intval($n); }); ``` or in this case, simply $newIds = array_filter($ids, 'intval');. Does the same reasoning apply to https://3v4l.org/ZCgRe ? It seems internal functions that accept references will function correctly but still throw the same warning. ------------------------------------------------------------------------ [2020-07-13 12:54:46] nikic@php.net This is an intentional change, now documented with https://github.com/php/php-src/commit/2edc5e00ac5ceef6429c3ef4651745efa97a13d8. As the the inverted message, I can see where you're coming from there... The message appears because array_filter() internally calls the callback with a value, but the function expects a reference, thus the warning in this form. ------------------------------------------------------------------------ [2020-07-13 12:21:33] sjon@php.net Description: ------------ I'm not 100% sure this is a bug but both array_walk and array filter throw warnings when variables are passed by reference. Either the message is inverted (they don't accept variables by reference) or it's incorrectly thrown Originally found as https://3v4l.org/WH94Q Test script: --------------- $ids = array("8479"); $newIds = array_filter($ids, function(&$n) { $n = intVal($n); }); Expected result: ---------------- no warning Actual result: -------------- Warning: {closure}(): Argument #1 ($n) must be passed by reference, value given in /in/WH94Q on line 7 ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=79850&edit=1