为什么xpath删除html特殊字符？ [英] why does xpath remove html special characters?

问题描述

为什么这么做

$html = '<a href="/browse/product.do?cid=1&amp;vid=1&amp;pid=1" class="productItemName">what is going on here</a>';

$dom = new DOMDocument();
$dom->loadhtml($html);
$xpath = new DOMXPath($dom);

$selectors['link'] = '//a/@href';
$links_nodeList = $xpath->query($selectors['link']);

foreach ($links_nodeList as $link) {
    $links[] = $link->nodeValue;
}

echo("<p>links</p>");
echo("<pre>");
print_r($links);
echo("</pre>");

输出

links

Array
(
    [0] => /browse/product.do?cid=1&vid=1&pid=1
)

而不是

links

Array
(
    [0] => /browse/product.do?cid=1&vid=1&pid=1
)

？

推荐答案

答案很简单：

& amp ; 是一种表示XML文档中字符& 的特殊方式。

& is a special way to represent the character "&" in an XML document.

这两个表示相同的字符。

当&符号的转义形式输出为文本（而不是XML）时，显示

When the escaped form of the ampersand is output as text (not as XML), showing it as "&" is correct.

@LarsH在他的评论中进一步阐述了< / strong>：

As further elaborated by @LarsH in his comment:

当您说 loadhtml（$ html）;时，您正在将字符串解析为HTML，
，这意味着将字符实体（如& ）解释为
为其表示的字符（如& ）。如果您想要将字符串
解释为& ，则需要转义与号，例如
。 & amp;

when you say loadhtml($html);, you are parsing the string as HTML, which means that character entities (like &) are interpreted into the characters they represent (like &). If you want a string that will be interpreted as &, you need to escape the ampersand, e.g. &

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