3v4l.org

run code in 200+ php & hhvm versions
Bugs & Features
<?php echo Serialize(Array(action=>"Hello"));
based on GZYWU
Output for 7.2.0
Warning: Use of undefined constant action - assumed 'action' (this will throw an Error in a future version of PHP) in /in/IvR4W on line 3 a:1:{s:6:"action";s:5:"Hello";}
Output for 4.3.0 - 7.1.10
Notice: Use of undefined constant action - assumed 'action' in /in/IvR4W on line 3 a:1:{s:6:"action";s:5:"Hello";}