How can I set the class only to parent categories in a custom loop?

Question

WordPress

By design, I need to display categories with subcategories on an individual page. The nuance is that subcategories and categories without child categories were displayed with pictures, and parent categories without pictures.
I output it like this

<div class="cat-container">
                     <?php

                             $categories = get_terms(
                                 'product_cat',
                                 array(
                                     'orderby'    => 'menu_order',
                                     'order' => 'ask',
                                     'hierarchical' => true,
                                     'hide_empty' => 1,
                                     'parent' => 0
                                 )
                             );

                               foreach($categories as $cat){
                              $cat_thumb_id = get_woocommerce_term_meta( $cat->term_id, 'thumbnail_id', true );
                              $cat_thumb_url = wp_get_attachment_image_src( $cat_thumb_id, 'thumbnail-size' )[0];
                              ?>
                                    <div class="cat-sub">
                                        <?php $temp_cat = get_terms(
                                                 'product_cat',
                                                 array(
                                                     'orderby'    => 'menu_order',
                                                     'order' => 'ask',
                                                     'hierarchical' => true,
                                                     'hide_empty' => 1,
                                                     'parent' => $cat->term_id
                                                 )
                                             );

                                             $class='';
                                             if($temp_cat) {$class='has_child';} else {$class='no_child';} ?>
                                          <div class="parent-item-wrap d-flex justify-content-center">
                                             <div class="cat-parent-item col-lg-5 col-12 product-category">
                                                <div class="subcategory-inner">
                                                    <a href="<?php echo get_term_link( $cat->term_id,'product_cat' )?>" target='_blank'>
                                                      <img src="<?php echo $cat_thumb_url; ?>" alt="" /> 
                                                      <h2 class="woocommerce-loop-category__title"><?php echo $cat->name?></h2>
                                                   </a>
                                                 </div>
                                            </div>
                                         </div>                                  
                                 <?php
                                    if($temp_cat){?>
                                       <div class="child-items d-flex flex-wrap align-items-stretch">
                                              <?php foreach($temp_cat as $temp){
                                               $cat_thumb_id = get_woocommerce_term_meta( $temp->term_id, 'thumbnail_id', true );
                                               $cat_thumb_url = wp_get_attachment_image_src( $cat_thumb_id, 'thumbnail-size' )[0]; 
                                                ?> 
                                                <div class="cat-item col-xl-3 col-md-4 col-sm-6 col-12 product-category">
                                                   <div class="subcategory-inner">
                                                      <a href="<?php echo get_term_link( $temp->term_id,'product_cat' )?>" target='_blank'>
                                                         <img src="<?php echo $cat_thumb_url; ?>" alt="" />                             
                                                         <h2 class="woocommerce-loop-category__title"><?php echo $temp->name; ?></h2>  
                                                      </a>
                                                   </div>
                                                </div>   
                                          <?php }?>
                                       </div>
                                       <?php } ?>
                              </div>      
                        <?php } ?>      
                  </div>

If I just remove from .cat-parent-item, then the images will not be displayed in categories that are neither parent nor child, which do not have children. When creating a menu, there is a class like has_children, how can I attach it only to parent categories?
<img src="<?php echo $cat_thumb_url; ?>" alt="" />

Answer 1

The object that returns get_terms()has a key parent , by which you can check the existence of the parent category

$categories = get_terms();
foreach ( $categories as $key => $category ) {
  if ( $category->parent == 0 ) {
    # нет родителя
  } else {
    # есть родитель
  }
}

If you wish, you can wrap it all in a separate function.

function is_category_parent( $cat_id ) {
  $category = get_category( $cat_id );
  if ( $category->parent == 0 ) {
    return true;
  }
  return false;
}

And use her

if ( is_category_parent( $cat_id ) ) {
  // категория имеет родителя
}