How to Add featured thumbnail to admin post columns

Adding this snippet to the functions.php of your WordPress theme will add the featured thumbnail to the post listing within the WordPress admin. This is a featured I added to my theme so that when creating posts I could more easily see what posts I had added thumbnails to.

add_filter('manage_posts_columns', 'posts_columns', 5); add_action('manage_posts_custom_column', 'posts_custom_columns', 5, 2); function posts_columns($defaults){ $defaults['admin_post_thumbs'] = __('Thumbs'); return $defaults; } function posts_custom_columns($column_name, $id){ if($column_name === 'admin_post_thumbs'){ echo the_post_thumbnail( 'featured-thumbnail' ); } }