DOMXPath->__construct()	DOMXPath->query()

	Last updated: Mon, 16 Jul 2012

DOMXPath->evaluate()

(no version information, might be only in CVS)

DOMXPath->evaluate() -- Evaluates the given XPath expression and returns a typed result if possible.

说明

class DOMXPath {

mixed evaluate ( string expression [, DOMNode contextnode] )

}

Executes the given XPath expression and returns a typed result if possible.

参数

expression: The XPath expression to execute.
contextnode: The optional contextnode can be specified for doing relative XPath queries. By default, the queries are relative to the root element.

返回值

Returns a typed result if possible or a DOMNodeList containing all nodes matching the given XPath expression.

例

例子 1. Getting the count of all the english books

<?php $doc = new DOMDocument; $doc->load('book.xml'); $xpath = new DOMXPath($doc); $tbody = $doc->getElementsByTagName('tbody')->item(0); // our query is relative to the tbody node $query = 'count(row/entry[. = "en"])'; $entries = $xpath->evaluate($query, $tbody); echo "There are $entries english books\n"; ?>
上例将输出：
There are 2 english books

参见

DOMXPath->query()

DOMXPath->__construct()	DOMXPath->query()

	Last updated: Mon, 16 Jul 2012


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