How can PHP be used to extract specific content from attribute values within HTML elements?

To extract specific content from attribute values within HTML elements using PHP, you can use a combination of string manipulation functions and regular expressions. One approach is to use PHP's DOMDocument class to parse the HTML and then extract the attribute values using XPath queries. Another approach is to use PHP's built-in functions like preg_match() to extract the content based on patterns within the attribute values.

// Sample HTML content
$html = '<div class="container">
            <a href="https://example.com">Link</a>
         </div>';

// Create a DOMDocument object
$dom = new DOMDocument();
$dom->loadHTML($html);

// Use XPath to extract specific attribute values
$xpath = new DOMXPath($dom);
$elements = $xpath->query("//a/@href");

foreach ($elements as $element) {
    echo $element->nodeValue; // Output: https://example.com
}