核心没有内置任何东西，但您可以轻松地自己制作这样的东西。这里有一个例子，可以给posts类提供post-count-1、post-count-2、post-count-3、post-count-1等等。。。。2.3.1等：

<?php
\\\\ start the counter at 1
$counter = 1;
\\\\ start the loop
while->have_posts() : the_post();
\\\\ figure out our count
$count = \'post-count-\' . $counter % 3;
?>
<article <?php post_class( $count ); ?>>
    \\\\ some more stuff like the title and content
</article>
<?php
\\\\ advance the counter
$counter++;
\\\\ keep looping until the end
endwhile;
?>

附录：我应该补充一点，如果您不需要广泛的浏览器支持（：nth-child（）CSS选择器确实是正确的解决方案，如果您需要纯粹用于样式设计的类。jQuery还支持这个选择器，如果需要更好的CSS浏览器支持，可以使用它在页面加载后添加类。

不完全是，但WordPress确实有body_class 和post_class , 默认情况下，它将为您提供自定义选择器，可以使用您选择的任何名称或变量进一步自定义。

http://codex.wordpress.org/Function_Reference/body_class
http://codex.wordpress.org/Function_Reference/post_class

例如，您还可以将其用作过滤器；

add_filter(\'body_class\',\'my_class_names\');

function my_class_names($classes) {
    // Some conditional
    $classes[] = \'my-custom-class-name\';
    // return the $classes array
    return $classes;
}

这是Rails中我最喜欢的助手之一（Shopify用其液态模板语言创建了到的链接）。我为WordPress编写了一个类似的函数，请欣赏：

/**
 * Cycle/alternate unlimited values of a given array.
 * For instance, if you call this function five times with wp_cycle(\'three\', \'two\', \'one\'),
 * you will in return get: three two one three two. This is useful for loops and allows you to
 * cycle classes.
 * For instance, foreach ($posts as $post) { echo \'<div class="\'.wp_cycle(\'odd\',\'even\').\'">...</div>\'; }
 * would alternate between <div class="odd">...</div> and <div class="even">...</div>. Neat, huh?
 * You can pass any data as args and as many as you want, e.g. wp_cycle(array(\'foo\', \'bar\'), false, 5, \'silly\')
 *
 * @param mixed Accepts unlimited args
 * @return mixed
 * @author Matthew Boynes
 */
function wp_cycle() {
    global $wp_cycle_curr_index;
    $args = func_get_args();
    $fingerprint = substr( sha1( serialize( $args ) ), 0, 7 );
    if ( !is_array( $wp_cycle_curr_index) ) $wp_cycle_curr_index = array();
    if ( !isset( $wp_cycle_curr_index[ $fingerprint ] ) || !is_int( $wp_cycle_curr_index[ $fingerprint ] ) ) $wp_cycle_curr_index[ $fingerprint ] = -1;
    $wp_cycle_curr_index[ $fingerprint ] = ++$wp_cycle_curr_index[ $fingerprint ] % count( $args );
    return $args[ $wp_cycle_curr_index[ $fingerprint ] ];
}