WordPress函数Get_the_category获取分类信息详解

function get_the_category( $id = false ) {     $categories = get_the_terms( $id, 'category' );     if ( ! $categories || is_wp_error( $categories ) )         $categories = array();       $categories = array_values( $categories );       foreach ( array_keys( $categories ) as $key ) {         _make_cat_compat( $categories[$key] );     }       /**      * Filters the array of categories to return for a post.      *      * @since 3.1.0      * @since 4.4.0 Added `$id` parameter.      *      * @param array $categories An array of categories to return for the post.      * @param int   $id         ID of the post.      */     return apply_filters( 'get_the_categories', $categories, $id ); }