dom - php DomDocument: how can i print an attribute of an element?

how do I print the an attribute of an element?

example:

$doc = new DOMDocument();
@$doc->loadHTML($page);
$xpath = new DOMXPath($doc);
$arts= $xpath->query("/td");

foreach ($arts as $art) {
  here i wanna print the attribute class of the td element, how do i do so ?
}

Answer

use DOMElement::getAttribute

$art->getAttribute('class');

also, simpleHTMLDOM is more suitable for dealing with html:

$html = str_get_html($page);
foreach($html->find('td') as $element) 
   echo $element->class.'
';

}