Craft\FormBuilder2TwigExtension::camelCase PHP Method

    public function camelCase($str)
    {
        $i = array("-", "_");
        $str = preg_replace('/([a-z])([A-Z])/', "\\1 \\2", $str);
        $str = preg_replace('@[^a-zA-Z0-9\\-_ ]+@', '', $str);
        $str = str_replace($i, ' ', $str);
        $str = str_replace(' ', '', ucwords(strtolower($str)));
        $str = strtolower(substr($str, 0, 1)) . substr($str, 1);
        return $str;
    }