3v4l.org

run code in 500+ PHP versions simultaneously
<?php $form_state = array(); $key = NULL; $entity = $form_state[$key];
Output for 5.6.0 - 5.6.40, 7.0.0 - 7.0.33, 7.1.0 - 7.1.33, 7.2.0 - 7.2.34, 7.3.0 - 7.3.31, 7.4.0 - 7.4.33
Notice: Undefined index: in /in/u5cNk on line 4
Output for 7.3.32 - 7.3.33
Output for 8.0.0 - 8.0.30, 8.1.0 - 8.1.34, 8.2.0 - 8.2.34, 8.3.0 - 8.3.35, 8.4.1 - 8.4.26
Warning: Undefined array key "" in /in/u5cNk on line 4
Output for 8.5.0 - 8.5.11
Deprecated: Using null as an array offset is deprecated, use an empty string instead in /in/u5cNk on line 4 Warning: Undefined array key "" in /in/u5cNk on line 4
preferences:
42.03 ms | 1150 KiB | 15 Q