打开网址并计算包含的链接数量

I'm looking for a solution using PHP/Dom to get number of links on each page. I use PHPDOM library and this is my own PHP code:

public function count_page_links($url = "https://www.rootdomain.com"){
    $html = file_get_html($url);
    foreach($html->find('a') as $link){
        $headers = @get_headers($link->href);
        if(strpos($headers[0], "200")){

        }
    }
}