- preg_replace_callback: documentation ( source)
- strtolower: documentation ( source)
<?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');