object(DOMNodeList) object(DOMElement)

$eBayTime = $responseDoc->getElementsByTagName('Timestamp');
object(DOMNodeList)    $eBayTime
这种对象，取长度 $eBayTime->length
取值   $eBayTime->item(0)
取值的对象是 object(DOMElement) $eBayTime->item(0)
取值       $eBayTime->item(0)->nodeValue