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apply_filters( 'has_post_thumbnail', bool $has_thumbnail, int|WP_Post|null $post, int|string $thumbnail_id )

Filters whether a post has a post thumbnail.

$has_thumbnail: (bool) true if the post has a post thumbnail, otherwise false.
$post: (int|WP_Post|null) Post ID or WP_Post object. Default is global $post.
$thumbnail_id: (int|string) Post thumbnail ID or empty string.

Used By	Description
wp-includes/post-thumbnail-template.php: has_post_thumbnail()	Determines whether a post has an image attached.

Version	Description
5.1.0	Introduced.

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Licensed under the GNU GPLv2+ License.
https://developer.wordpress.org/reference/hooks/has_post_thumbnail