<?php 
$xml=<<<XML
<cars> 
<car name="Volvo"> 
<child/> 
<child/> 
<child/> 
<child/> 
</car> 
<car name="BMW"> 
<child/> 
<child/> 
</car> 
</cars> 
XML;
$elem=new SimpleXMLElement($xml); 
foreach ($elem as $car) 
{ 
printf("%s has %d children.<br>", $car['name'], $car->count()); 
} 
?>

count();