Req #70771 [Opn->Nab]: foreach($array['non_existant_key'] as &$row) silently modifies array

Edit report at https://bugs.php.net/bug.php?id=70771&edit=1 ID: 70771 Updated by: nikic@php.net Reported by: stuckinabox at live dot com Summary: foreach($array['non_existant_key'] as &$row) silently modifies array -Status: Open +Status: Not a bug Type: Feature/Change Request Package: Arrays related Operating System: all PHP Version: Irrelevant Block user comment: N Private report: N New Comment: A simpler case that illustrates the same issue: $ref =& $data['non_existant_key']; This will not throw a notice by design. You are allowed to take a reference to a key that does not exist yet -- it will be initialized to NULL. When you iterate by reference you are also implicitly creating a reference to the iterated entity. Previous Comments: ------------------------------------------------------------------------ [2015-10-22 17:29:42] stuckinabox at live dot com Description: ------------ Seems logical that an error should be thrown since that index doesnt exist in the array. instead, the index is silently added with a value of null. All versions of php >5.4 and all versions of HHVM are affected. Repro: https://3v4l.org/UNIe4 Test script: --------------- <?php $data = [ 'existant_key'=>[] ]; foreach($data['non_existant_key'] as &$row) { } print_r($data); ?> https://3v4l.org/UNIe4 Expected result: ---------------- undefined index Actual result: -------------- array is silently modified to include the non existant key ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=70771&edit=1