WordPressでカテゴリ(category)を取得する

$categories = get_categories(); 
foreach($categories as $category) {
  echo $category->term_id
  echo $category->name
  echo $category->slug
  echo $category->term_group
  echo $category->term_taxonomy_id
  echo $category->taxonomy
  echo $category->description
  echo $category->parent
  echo $category->count
  echo $category->cat_ID
  echo $category->category_count
  echo $category->category_description
  echo $category->cat_name
  echo $category->category_nicename
  echo $category->category_parent
}

<?php
  if(is_category()){
    $category = get_the_category()[0];
    echo '
      <div id="category-container">
        <h3 class="category__name">' . $category->name . '</h3>
        <span class="category__name">投稿数: ' . $category->category_count. '件</span>
        <div class="category__description post-content__text">' . $category->description. '</div>
      </div>
    ';
 };
?>