Difference Between Structure and Class in C++

Fatal error: Uncaught TypeError: count(): Argument #1 ($var) must be of type Countable|array, bool given in /var/www/html/wp-content/plugins/tabs-responsive/template/content.php:17 Stack trace: #0 /var/www/html/wp-content/plugins/tabs-responsive/template/shortcode.php(14): require() #1 /var/www/html/wp-includes/shortcodes.php(355): TABS_R_ShortCode(Array, '', 'TABS_R') #2 [internal function]: do_shortcode_tag(Array) #3 /var/www/html/wp-includes/shortcodes.php(227): preg_replace_callback('/\\[(\\[?)(TABS_R...', 'do_shortcode_ta...', '<p><img decodin...') #4 /var/www/html/wp-includes/class-wp-hook.php(308): do_shortcode('<p><img decodin...') #5 /var/www/html/wp-includes/plugin.php(205): WP_Hook->apply_filters('<p><img decodin...', Array) #6 /var/www/html/wp-includes/post-template.php(255): apply_filters('the_content', '<p><img src="ht...') #7 /var/www/html/wp-content/themes/infinity-news/template-parts/content.php(86): the_content() #8 /var/www/html/wp-includes/template.php(785): require('/var/www/html/w...') #9 /var/www/html/wp-includes/template.php(718): load_template('/var/www/html/w...', false, Array) #10 /var/www/html/wp-includes/general-template.php(204): locate_template(Array, true, false, Array) #11 /var/www/html/wp-content/themes/infinity-news/single.php(46): get_template_part('template-parts/...', 'post') #12 /var/www/html/wp-includes/template-loader.php(106): include('/var/www/html/w...') #13 /var/www/html/wp-blog-header.php(19): require_once('/var/www/html/w...') #14 /var/www/html/index.php(17): require('/var/www/html/w...') #15 {main} thrown in /var/www/html/wp-content/plugins/tabs-responsive/template/content.php on line 17