How do I add a class to every nth item in a php loop (wordpress)

Question

I have a Wordpress loop as follows:

 \'portfolio\' ) ); ?>
    have_po         


        

Answer 1

Implementation from the comments made:

 'portfolio' ) ); ?>
    have_posts() ) : $loop->the_post(); 
           if( $i % 4 == 0 )
             $class = 'omega';
           else
             $class = ''; 
        ?>