我的循环返回五篇文章，HTML应该是这样的。。

<ul>
    <li class="topfive"> ... </li>
    <li class="topfive"> ... </li>
    <li class="topfive"> ... </li>
    <li class="topfive"> ... </li>
    <li class="topfive"> ... </li>
</ul>

而且，我需要根据出现的顺序以编程方式向它们添加类，类似这样的。。

<ul>
    <li class="topfive first"> ... </li>
    <li class="topfive second"> ... </li>
    <li class="topfive third"> ... </li>
    <li class="topfive fourth"> ... </li>
    <li class="topfive fifth"> ... </li>
</ul>

下面是我用来创建循环的代码：

function custom_top_products() {
    $args = array (
                \'post_type\' => \'products\',
                \'post_status\' => \'publish\',
                \'orderby\' => \'comment_count\',
                \'posts_per_page\' => 5
            );
        $posts = new WP_Query( $args );

        ?>
        <div id="topproducts" class="ratingbox">
            <h3 class="rbh3">Top 5 Products</h3>
            <div class="topproductcontainer">
        <?php
            if ( $posts->have_posts() ) {
                while ( $posts->have_posts() ) {
                $posts->the_post();
            ?>
                <li class="topfive"><a href="<?php the_permalink(); ?>" title="<?php the_title_attribute(); ?>"><?php the_title(); ?></a></li>          
            <?php               
            } else {
                echo \'<p class="trc">Sorry, No Popular Products Found</p>\';
            }
            wp_reset_postdata();
        ?>
            </div>
        </div>      
        <?php
}

请帮忙

function custom_top_products() {
    $classes = array( \'first\', \'second\', \'third\', \'fourth\', \'fifth\' );
    $classes_count = count( $classes );

    $posts = new WP_Query( array(
        \'post_type\' => \'products\',
        \'post_status\' => \'publish\',
        \'orderby\' => \'comment_count\',
        \'posts_per_page\' => 5
    ) );

    $i = 0;

    ?><div id="topproducts" class="ratingbox">
        <h3 class="rbh3">Top 5 Products</h3>
        <div class="topproductcontainer"><?php
            if ( $posts->have_posts() ) {
                while ( $posts->have_posts() ) {
                    $posts->the_post();
                    ?><li class="topfive <?php echo $classes[$i++ % $classes_count] ?>">
                        <a href="<?php the_permalink(); ?>" title="<?php the_title_attribute(); ?>"><?php the_title(); ?></a>
                    </li><?php
                }

                wp_reset_postdata();
            } else {
                echo \'<p class="trc">Sorry, No Popular Products Found</p>\';
            }
            ?></div>
    </div><?php
}