PHP | DOMXPath __construct()函数
DOMXPath::__construct()函数是PHP中的一个内置函数,用于创建 DOMXPath 的实例。
句法:
bool DOMXPath::__construct( DOMDocument $doc )
参数:此函数接受单个参数$doc ,该参数保存与 DOMXPath 关联的 DOMDocument。
下面的例子说明了PHP中的DOMXPath::__construct()函数:
示例 1:
Hello World
XML;
// Load the XML
$document->loadXML($xml);
// Create a new DOMXPath instance
$xpath = new DOMXPath($document);
// Get the element
$tbody = $document->
getElementsByTagName('content')->item(0);
// Get the element with name content
$query = '//content';
// Evaluate the query
$entries = $xpath->evaluate($query, $tbody);
echo $entries[0]->nodeValue;
?>
输出:
Hello World
示例 2:
First
Second
Third
XML;
// Load the XML
$document->loadXML($xml);
// Create a new DOMXPath instance
$xpath = new DOMXPath($document);
// Get the root element
$tbody = $document->
getElementsByTagName('root')->item(0);
// Count the number of element with
// name content
$query = 'count(//content)';
// Evaluate the query
$entries = $xpath->evaluate($query, $tbody);
echo $entries;
?>
输出:
3
参考: https://www. PHP.net/manual/en/domxpath.construct。 PHP