3v4l.org

run code in 200+ php & hhvm versions
Bugs & Features
<?php $a = ['a1' => x];
Output for 7.2.0
Warning: Use of undefined constant x - assumed 'x' (this will throw an Error in a future version of PHP) in /in/LH6YX on line 3
Output for 5.4.11 - 7.1.10
Notice: Use of undefined constant x - assumed 'x' in /in/LH6YX on line 3
Output for 5.3.21 - 5.3.29
Parse error: syntax error, unexpected '[' in /in/LH6YX on line 3
Process exited with code 255.