DomQuery::count();

Simply returns the number of matched results from the last XPath query. May also use a previously returned instance of XPathResultIterator.

 $DomQuery = new DomQuery;
 echo $DomQuery->load($xml, '//root')->count();
 echo $DomQuery->count();
 echo count($DomQuery);
 echo count($XPathResultIterator);

Definition:

public function count(XPathResultIterator $XPathResultIterator = null)

Parameters: