DOMXPath::evaluate
(PHP 5 >= 5.1.0, PHP 7)
DOMXPath::evaluate — Evaluates the given XPath expression and returns a typed result if possible
Description
$expression
[, DOMNode $contextnode
[, bool $registerNodeNS
= TRUE
]] ) : mixed
Executes the given XPath expression
and returns
a typed result if possible.
Parameters
-
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. -
registerNodeNS
-
The optional
registerNodeNS
can be specified to disable automatic registration of the context node.
Return Values
Returns a typed result if possible or a DOMNodeList
containing all nodes matching the given XPath expression
.
If the expression
is malformed or the
contextnode
is invalid,
DOMXPath::evaluate() returns FALSE
.
Examples
Example #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";
?>
The above example will output:
There are 2 english books
English translation
You have asked to visit this site in English. For now, only the interface is translated, but not all the content yet.If you want to help me in translations, your contribution is welcome. All you need to do is register on the site, and send me a message asking me to add you to the group of translators, which will give you the opportunity to translate the pages you want. A link at the bottom of each translated page indicates that you are the translator, and has a link to your profile.
Thank you in advance.
Document created the 30/01/2003, last modified the 26/10/2018
Source of the printed document:https://www.gaudry.be/en/php-rf-domxpath.evaluate.html
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References
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