在网站上，它有一个复选框HTML代码，如下所示：
<input type="checkbox" name="mycheckbox" id="mycheckbox" value="123" checked="checked">
如何检查复选框是否已通过xPath选中？我本质上只是想要一个布尔值，如果它被选中，就会告诉我True。不过我不确定该怎么做。
<?php
$dom = new DOMDocument();
$content = file_get_content('https://example.com');
@$dom->loadHtml($content);
// Xpath to the checkbox
$xp = new DOMXPath($dom);
$xpath = '//*[@id="mycheckbox"]'; // xPath to the checkbox
$answer = $xp->evaluate('string(' . $xpath . ')');
您对XPath考虑太多了。evaluate()在这里计算XPath字符串的结果——不需要将其转换为要计算的PHP表达式。
$dom = new DOMDocument();
$content = '<html><body><input type="checkbox" name="mycheckbox" id="mycheckbox" value="123" checked="checked"></body></html>';
@$dom->loadHtml($content);
// Xpath to the checkbox
$xp = new DOMXPath($dom);
$xpath = '//*[@id="mycheckbox"]'; // xPath to the checkbox
$answer = $xp->evaluate($xpath);
// If we got an answer it'll be in a DOMNodeList, but as we're searching
// for an ID there should be only one, in the zeroth element
if ($answer->length) {
// Then we need to get the attribute list
$attr = $answer->item(0)->attributes;
// now we can check if the attribute exists and what its value is.
if ($chk = $attr->getNamedItem('checked')) {
echo $chk = $attr->getNamedItem('checked')->nodeValue; //checked
} else {
echo "No checked attribute";
}
} else {
echo "Element with specified ID not found";
}