php - How can I use a foreach loop and set small variations at fixed positions? -

i search long time on forum , can't find solution problem.

i need create foreach loop 12 elements 3 of them have different class.

this have done far:

$result = $db->query("select `views` `views` `views` = `id` , date_sub(curdate(),interval 7 day) <= date(`views`.`time`) order `id` desc limit 12");  while($row = $result->fetch_assoc()) {     $users[] = $row; }  $output .= '<ul>'; foreach($rows $row) {     $output .= '<li class="grid__item"></li>'; } $output .= '<ul>';  return $output; 

how can add different class li objects @ 2, 8 , 12 position?

to output this:

<ul>                         <li class="grid__item"></li>     <li class="grid__item grid__item--deco grid__item--deco-1"></li>     <li class="grid__item"></li>     <li class="grid__item"></li>     <li class="grid__item"></li>     <li class="grid__item"></li>     <li class="grid__item"></li>     <li class="grid__item grid__item--deco grid__item--deco-2"></li>     <li class="grid__item"></li>     <li class="grid__item"></li>     <li class="grid__item"></li>     <li class="grid__item grid__item--deco grid__item--deco-3"></li> </ul> 

just use key of foreach, set additional class inside loop block. add if condition:

$i = 1; $class_keys = array(2, 8, 12); $output = '<ul>'; foreach($rows $key => $row) {               //  ^ use     $default_class = 'grid__item';     if(in_array($key + 1, $class_keys)) {         $default_class .= " grid__item--deco grid__item--deco-{$i}";         $i++;     }     $output .= "<li class=\"$default_class\"></li>";  } $output .= '<ul>';