php Xpath返回:非对象

Question

使用PHP XPath我在xml文件中搜索客户:

$this->xpath->query(/custumer/new[id="222"])->item(0)->nodeValue;

但是如果这个客户在xml文件中不存在,我会收到错误:

Notice: Trying to get property of non-object in D:\www\test.php on line 17

如何避免这个错误？

Answer 1

首先检查XPATH-> query返回的nodeList 的长度.如果它不是0,则有一个对象.

$nodelist = $this->xpath->query('/custumer/new[@id="222"]');

if($nodelist->length)//a DOMNodelist has a length-property
{
  $result = $nodelist->item(0)->nodeValue;
}