DOMXPath::evaluate
(PHP 5 >= 5.1.0, PHP 7)
DOMXPath::evaluate — Evaluates the given XPath expression and returns a typed result if possible
Description
public DOMXPath::evaluate ( string $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
contextnodecan be specified for doing relative XPath queries. By default, the queries are relative to the root element. -
registerNodeNS -
The optional
registerNodeNScan 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
See Also
- DOMXPath::query() - Evaluates the given XPath expression
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https://www.php.net/manual/en/domxpath.evaluate.php