如何在PHP语言中通过SImpleXML访问XML数据

<?php
// 加载XML数据
$xml = simplexml_load_string('<bookstore>
                                <book>
                                    <title>Harry Potter</title>
                                    <author>J.K. Rowling</author>
                                    <year>2005</year>
                                </book>
                                <book>
                                    <title>The Lord of the Rings</title>
                                    <author>J.R.R. Tolkien</author>
                                    <year>2003</year>
                                </book>
                            </bookstore>');

// 访问XML元素
echo "Title: " . $xml->book[0]->title . "<br>";
echo "Author: " . $xml->book[0]->author . "<br>";
echo "Year: " . $xml->book[0]->year . "<br>";

// 遍历XML数据
foreach ($xml->book as $book) {
    echo "Title: " . $book->title . "<br>";
    echo "Author: " . $book->author . "<br>";
    echo "Year: " . $book->year . "<br>";
}
?>