Generate class on list-item

Question

I want php to print a class on each fourth list-item. Is that possible?

<ul>
  <li>List-item 1</li>
  <li>List-item 1</li> 
  <li>List-item</li> 
  <li class="new_class">List-item</li>
  <li>List-item 1</li>
  <li>List-item 1</li> 
  <li>List-item</li> 
  <li class="new_class">List-item</li> 
</ul>

Answer 1

In your for loop, iterate an index and if ( $index % 4 == 0 ) { echo 'class="new_class"'; }

Answer 2

$items = array ('List-item 1', 'List-item 1', 'List-item', 'List-item', 'List-item 1', 'List-item 1', 'List-item', 'List-item');

printf("<ul>");

for ($index=0; $index < count($items); $index++)
{
    if ($index%4 == 0)
    {
        $class = ' class="new_class"';
    }
    else
    {
        $class = '';
    }
    printf("<li%s>%s</li>", $class, $item[$index]);
}

printf("</ul>");