$current_letter = '';foreach($names as $name){ $first_letter = substr($name, 0, 1); if($first_letter !== $current_letter){ if(!empty($current_letter)){ echo '</ul>'; } echo '<h2>' . $first_letter . '</h2><ul>'; $current_letter = $first_letter; } echo '<li>' . $name . '</li>';}echo '</ul>';