Modulus example to create rows in a grid

mod_rows.php

<div class="row">
<?php
// $posts is some content to loop over and output.
$posts_count = 0;
foreach ( $posts as $post ) :
	echo $post;
	if ( $posts_count % 3 == 2 ) : // Fires every 3rd item since we are counting from 0. ?>
	    </div><div class="row>
	<?php endif;
	$posts_count++;
endforeach;
?>
</div>