PHP count() 函数

<?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());
}
?>