Lägga på odd/even-klasser med PHP

<?php $var = 4; ?>
<div class="var-<?php echo ($var++ % 2); ?>">adds class 0 if $var is even, otherwise 1</div>

Or with an if statement for adding custom class names (for loop for demonstration purpose):

<?php for ($var = 0; $var <= 10; $var++) : ?>
<div class="<?php if ($var % 2 == 0) : echo 'even'; else : echo 'odd'; endif; ?>">snel hest <?php echo $var; ?></div>
<?php endfor; ?>