3v4l.org

run code in 200+ php & hhvm versions
Bugs & Features
<?php $a=“”; for($i=0;$i<=3;$i++){ $a .= $i; } echo $a;
based on ZhouX
Output for 7.2.0
Warning: Use of undefined constant “” - assumed '“”' (this will throw an Error in a future version of PHP) in /in/WKrTf on line 2 “”0123
Output for 5.3.20 - 7.1.10
Notice: Use of undefined constant “” - assumed '“”' in /in/WKrTf on line 2 “”0123