get_the_post_thumbnail_caption()

get_the_post_thumbnail_caption( int|WP_Post|null $post = null ): string

function get_the_post_thumbnail_caption( $post = null ) {
	$post_thumbnail_id = get_post_thumbnail_id( $post );

	if ( ! $post_thumbnail_id ) {
		return '';
	}

	$caption = wp_get_attachment_caption( $post_thumbnail_id );

	if ( ! $caption ) {
		$caption = '';
	}

	return $caption;
}