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<?php $obj = new stdClass; $obj->a = &$obj->b; $obj->b = 1; var_dump($obj);
Output for 5.0.0 - 5.0.5, 5.1.0 - 5.1.6, 5.2.0 - 5.2.17, 5.3.0 - 5.3.29, 5.4.0 - 5.4.45, 5.5.0 - 5.5.38, 5.6.0 - 5.6.28, 7.1.0 - 7.1.20, 7.2.0 - 7.2.33, 7.3.16 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.27, 8.2.0 - 8.2.17, 8.3.0 - 8.3.4
object(stdClass)#1 (2) { ["b"]=> &int(1) ["a"]=> &int(1) }
Output for 7.0.0 - 7.0.20
object(stdClass)#1 (2) { ["a"]=> &int(1) ["b"]=> &int(1) }
Output for 4.3.0 - 4.3.11, 4.4.0 - 4.4.9
object(stdClass)(2) { ["b"]=> &int(1) ["a"]=> &int(1) }

preferences:
255.01 ms | 401 KiB | 350 Q