3v4l.org

run code in 150+ php & hhvm versions
Bugs & Features
<?php $d = array(); $h = 'd'; $$h[] = 'test'; print_r($d);
Output for 7.0.0 - 7.1.0
Array ( [0] => test )
Output for 4.3.2 - 5.6.28, hhvm-3.10.0 - 3.12.0
Fatal error: Cannot use [] for reading in /in/BJXN7 on line 5
Process exited with code 255.
Output for 4.3.0 - 4.3.1
Fatal error: Cannot use [] for reading in /in/BJXN7 on line 5