DOMNode::lookupNamespaceUri()

(PHP 5, PHP 7)

Gets the namespace URI of the node based on the prefix

说明

publicDOMNode::lookupNamespaceUri(string $prefix): string

Gets the namespace URI of the node based on the$prefix.

参数

$prefix: The prefix of the namespace.

返回值

The namespace URI of the node.

参见

DOMNode::lookupPrefix() Gets the namespace prefix of the node based on the namespace URI

Simple way to get the URI of the default namespace:
<?php
  $document = new DOMDocument();
  $document->load($xml_file);
  $uri = $document->documentElement->lookupnamespaceURI(NULL);
?>

You have to pass *null* to lookupNamespaceURI if you want to read the default namespace. Passing an empty string doesn't work - even though the documentation says that lookupNamespaceURI takes a string as argument (and null would just be converted to an empty string).