PHP DOMXPath使用示例，帮助理解evaluate、query及获取3种结果方式

2025-4-07 18:56:32

示例代码：

<?php

$html = <<<HTML
<article>
    <h2>Article Title</h2>
    <div class="entry-content">你好
        <p>This is the content of the article.</p>
        <p>This is the content of the article.</p>
        <p>This is the content of the <span>article</span>.</p>
    </div>
</article>
HTML;

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

$title = $xpath->evaluate('string(//h2');

// 查询 div 元素
$contentNode = $xpath->query('//div[@class="entry-content"]')->item(0);

// 初始化内容字符串
$content = '';

// 检查是否找到了目标节点
if ($contentNode) {
    // 遍历目标节点的所有子节点
    foreach ($contentNode->childNodes as $childNode) {
        // 将每个子节点保存为 HTML 字符串并拼接到内容中
        $content .= $dom->saveHTML($childNode);
    }
}

$contentNode2 = $xpath->query('//div[@class="entry-content"]')->item(0);
// 获取该节点及其子节点的 HTML 内容
if ($contentNode2) {
    $content2 = $dom->saveHTML($contentNode2);
} else {
    $content2 = '';
}

$content3 = $xpath->evaluate('string(//div[@class="entry-content"])');

echo "Title: $titlen"; 
echo "Content: $contentn";
echo "Content: $content2n";
echo "Content: $content3n";
?>

输出结果：

Title: Article Title

Content: 你好
<p>This is the content of the article.</p>
<p>This is the content of the article.</p>
<p>This is the content of the <span>article</span>.</p>

Content2: <div class="entry-content">你好
<p>This is the content of the article.</p>
<p>This is the content of the article.</p>
<p>This is the content of the <span>article</span>.</p>
</div>

Content3: 你好
This is the content of the article.
This is the content of the article.
This is the content of the article.