3v4l.org

run code in 300+ PHP versions simultaneously
<?php for ($x=0,$a=null;$x<28;$x++) { $chars = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789-_'; $a .= substr($chars,mt_rand(0,63),1); } echo $a;

preferences:
29.75 ms | 402 KiB | 5 Q