3v4l.org

run code in 300+ PHP versions simultaneously
<?php function v2($value) { return preg_replace_callback('/([A-Z])/', function($char) { return '_'.strtolower($char[1]); }, lcfirst($value)); } for($x = 0; $x < 10000; $x++){ $foo = v2('foo_bar_baz_bee'); if($x = 0) echo $foo; }

preferences:
35.7 ms | 402 KiB | 5 Q