Alternating layouts ACF / PHP

gistfile1.txt

<?php $counter = 0; if(get_sub_field('timeline')): ?><?php while(has_sub_field('timeline')): ?>

    <?php if ($counter % 2 === 0) :?>

     <?php else: ?>

    <?php endif; ?>

<?php $counter++; endwhile; ?><?php endif; ?>

---------------------------

$layout = 1;

<?php if ( $layout & 1 ) { ?>

<?php } else { ?>

<?php } ?>

$layout++;