简单的XML使用PHP在多个级别上查找父对象

<?php
$xml = '
<books>
    <book>
        <title>Book 1</title>
        <author>Author 1</author>
    </book>
    <book>
        <title>Book 2</title>
        <author>Author 2</author>
    </book>
</books>';

// 将XML字符串加载为SimpleXMLElement对象
$books = new SimpleXMLElement($xml);

// 查找所有book元素
foreach ($books->book as $book) {
    // 获取当前book元素的父对象（books元素）
    $parent = $book->xpath('parent::*');
    
    // 输出父对象的名称
    echo "Parent object: " . $parent[0]->getName() . "\n";
    
    // 输出当前book元素的标题和作者
    echo "Title: " . $book->title . "\n";
    echo "Author: " . $book->author . "\n\n";
}
?>