3v4l.org

run code in 150+ php & hhvm versions
Bugs & Features
<?php $a = ''; $a[] = 'foo'; var_dump($a);
Output for 7.1.0
Fatal error: Uncaught Error: [] operator not supported for strings in /in/ga6Dh:4 Stack trace: #0 {main} thrown in /in/ga6Dh on line 4
Process exited with code 255.
Output for 4.3.0 - 7.0.14
array(1) { [0]=> string(3) "foo" }