如何使用XPath获取节点的值？

Question

我如何使用XPath节点的值？

取得具有高于35

/bookstore/book[price>35.00] 

价格的所有节点但是，当我改变>为平等的=，查询失败。 请帮忙。顺便说一句，我使用PHP，但这应该不重要，因为XPath是通用的。

下面是我用

$xml = "<?xml version=\"1.0\" encoding=\"ISO-8859-1\"?> 
<bookstore> 
<book> 
    <title lang=\"eng\">Harry Potter</title> 
    <price>29.99</price> 
</book> 
<book> 
    <title lang=\"eng\">Learning XML</title> 
    <price>39.95</price> 
</book> 
</bookstore>"; $xml = new SimpleXMLElement($xml); 

    $name = 'Shiny Red'; 
    $nodes = $xml->xpath(sprintf('/bookstore/book[price>35.00]', $name)); 
    if (!empty($nodes)) { 
     printf('At least one building named "%s" found<hr/>', $name); 
    echo "<textarea style=\"width: 400px; height: 300px;\">";print_r($nodes); echo "</textarea>"; 
    } else { 
     printf('No building named "%s" found', $name); 
    }  

Answer 1

//bookstore/book/price[. ='35.00'] 

或

//bookstore/book[price='35.00'] 

的诀窍是在引号中的PHP代码和XML代码。节点值是文本。但是，您不会与'35 .00'匹配任何内容，但这是因为您的XML不包含具有该价格的书籍。匹配'39.95'将工作（测试）。

$xml = "<?xml version=\"1.0\" encoding=\"ISO-8859-1\"?> 
<bookstore> 
<book> 
    <title lang=\"eng\">Harry Potter</title> 
    <price>29.99</price> 
</book> 
<book> 
    <title lang=\"eng\">Learning XML</title> 
    <price>39.95</price> 
</book> 
</bookstore>"; $xml = new SimpleXMLElement($xml); 

    $name = 'Shiny Red'; 
    $nodes = $xml->xpath(sprintf('//bookstore/book/price[. = \'39.95\']', $name)); 
    if (!empty($nodes)) { 
     printf('At least one building named "%s" found<hr/>', $name); 
    echo "<textarea style=\"width: 400px; height: 300px;\">";print_r($nodes); echo "</textarea>"; 
    } else { 
     printf('No building named "%s" found', $name); 
    }