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(PHP 5 >= 5.1.0)
DOMXPath::evaluate — Evaluates the given XPath expression and returns a typed result if possible
$expression
[, DOMNode $contextnode
[, bool $registerNodeNS
= true
]] )
Executes the given XPath expression
and returns
a typed result if possible.
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.
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
.
Version | Description |
---|---|
5.3.3 |
The registerNodeNS parameter was added.
|
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