WordPress | Get Posts Odd or Even

get_posts_odd_even.php

<?php
$args = array(
	'posts_per_page' => 5,
	'post_type' => 'post'
);
$posts = get_posts( $args );
if ( $posts ) {
	$counter = 1;
	echo '<ul>';
	foreach ( $posts as $post ) : setup_postdata( $post );
		$post_title = get_the_title();
		echo '<li class="';
		if( $counter % 2 == 0 ) { // We use modulo to work out if there is a remainder when the counter is divided by 2.
			echo 'even';
		} else {
			echo 'odd';
		}
		echo '">';
		echo '<h2>' . $post_title . '</h2>';
		echo '</li>';
		$counter++;
	endforeach;
	echo '</ul>';
}
wp_reset_postdata();
?>

Odd or even get_posts

I was developing a site where content position varied from post to post depending on whether it was odd or even, so it wasn't something that could be solved using a CSS3 nth-child selector. This gist uses the Arithmetic Operator Modulo which converts its operands to integers before calculating a remainder. So by dividing by 2 we would expect no remainder on even values. Essentially it becomes an odd/even test.