3v4l.org

run code in 300+ PHP versions simultaneously
<?php function doSomething($string) { $string[0] = strtolower($string[0]); $func = create_function('$c', 'return "_" . strtolower($c[1]);'); return preg_replace_callback('/([A-Z])/', $func, $string); } echo doSomething('camelCase');

preferences:
47.26 ms | 402 KiB | 5 Q