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.
范例
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";
?>
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上例将输出： There are 2 english books |
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