Online PHP editor | refs for 27IaK

<?php $html = <<<HTML <div> <p>Paragraph one is okay </p> <h2>This will work without problem</h2> <p>Paragraph two is okay </p> <h2><a href="#">This heading has anchor</a></h2> <p>Paragraph one is okay </p> <h2> This heading start with space</h2> <p>Paragraph two is okay </p> <h3>1. <a href="https://www.example1.com/">This wont work</a></h3> <p>Paragraph one is okay </p> <h3>2. <a href="https://www.example2.com/">Not working</a></h3> <p>Paragraph two is okay </p> <h3>3. Neither this one</h3> <h3>But this works again</h3> </div> HTML; $dom = new DOMDocument; $dom->loadHTML($html, LIBXML_HTML_NOIMPLIED | LIBXML_HTML_NODEFDTD); $xpath = new DOMXPath($dom); foreach ($xpath->query("//h2 | //h3") as $node) { if (preg_match('~^\s*(?:\d+\.)?\s*\K\S+(?:\s+\S+){1,2}~', $node->nodeValue, $m)) { $node->setAttribute('id', str_replace(' ', '-', strtolower($m[0]))); } } echo $dom->saveHTML();