'echo $ category-＆gt; name;'没有回报

Question

我正在尝试遍历帖子列表并将其显示为类别作为标题。我很成功，唯一让陷入困境的是echo $ category-＆gt; name;似乎什么也没产生。我若添加回声“aaa”。 $分类 - ＆GT;名称; “aaa”出现了。

        <?php
            $args = array(
                'type'                     => 'cpt_referenzen',
                'orderby'                  => 'name',
                'order'                    => 'ASC',
                'hide_empty'               => 1,

                'number'                   => '',
                'taxonomy'                 => 'taxonomy');

        $categories = get_categories( $args );

        foreach ($categories as $category) {

            ?><h2><?php echo $category->name; ?></h1><?php

            $args = array( 'post_type' => 'cpt_referenzen', 'cpt_tax_referenz' => $category->slug, 'posts_per_page' => 30, 'orderby' => 'date' );
            $loop = new WP_Query( $args );

            while ( $loop->have_posts() ) : $loop->the_post();      
            ?><p>- <a href="<?php the_permalink() ?>" rel="bookmark" title="Permanent Link to <?php the_title_attribute(); ?>"><?php the_title(); ?></a></p><?php
            endwhile;   
        }       
        ?>