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# DOMXPath->evaluate()

(no version information, might be only in CVS)

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

## Descrição

class DOMXPath {
mixed evaluate ( string expression [, DOMNode contextnode] )
}

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

## Parâmetros

`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.

## Valores de retornado

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

## Exemplos

Exemplo 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"; ?>`

O exemplo acima irá imprimir:

    There are 2 english books

## Veja também

DOMXPath->query()

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DOMXPath->__construct() | Acima | DOMXPath->query()