Online PHP editor | refs for Ohb5l

<?php echo '<pre>'; $html = " consectetur adipiscing elit. Maecenas sit amet molestie enim. Nulla gravida mi sed ipsum pellentesque ut pulvinar orci consequat. Donec tempus rutrum urna at iaculis. Ut sagittis, tellus eu venenatis imperdiet, <ol> <li> <ol> <li></li> <li>sdaf</li> </ol> sem dolor mattis leo, </li> <li>in consequat elit lorem ut ligula.</li> </ol> Praessadf"; echo htmlspecialchars($html)." "; var_dump(check_html($html)); function check_html($html) { $tags = array(); preg_match_all('#<(/?[a-zA-Z]+)\b.*?>#im', $html, $tags); $tags = array_map('strtolower', $tags[1]); $lists = array('ul', 'ol'); $single_tags = array('br'); $tags_stack = new SplStack(); $lists_stack = new SplStack(); foreach ($tags as $tag) { if ($tag[0] != '/') { // start tag if (in_array($tag, $single_tags)) { // if single tag, just continue continue; } elseif (in_array($tag, $lists)) { $lists_stack->push($tag); // new list starts } $tags_stack->push($tag); } else { // end tag if (!$tags_stack->count()) { return false; // there aren't opened tags } $end_tag = trim($tag, '/'); // handle lists if (in_array($end_tag, $lists)) { if (!$lists_stack->count() || $lists_stack->pop() != $end_tag) { return false; // there are no opened lists or unclosed list tag } } elseif ($end_tag == 'li') { if (!$lists_stack->count()) { return false; // there are no opened lists } } if ($tags_stack->pop() != $end_tag) { return false; // unclosed tag } } } return !$tags_stack->count(); // true if stack is empty }