/**

    *WordPress 把当前文章分类的别名添加到 body 标签的 class

    *https://www.weixiaoduo.com/add-category-to-single/

*/

functionBing_add_category_to_single($classes){

    if(!is_single())return$classes;

    global$post;

    foreach((get_the_category($post->ID))as$category)$classes[]=$category->category_nicename;

    return$classes;

}

add_filter('body_class','Bing_add_category_to_single');