PHP: Camel case to title case function

helpers.php

if (!function_exists('camel_to_title')) {
    function camel_to_title($string = '')
    {
        // let's create spaces
        $intermediate = preg_replace('/(?!^)([[:upper:]][[:lower:]]+)/', ' $0', $string);

        // now upper case words
        return mb_convert_case($intermediate, MB_CASE_TITLE);
    }
}