WordPress函数post_type_exists()判断某个自定义文章类型是否存在

$post_type

(string) (必填) 自定义文章类型

默认值: None

示例：

if ( post_type_exists( 'book' ) ) {
   echo 'the Book post type exists';
}

源文件：

/**
 * Check if a post type is registered.
 *
 * @since 3.0.0
 *
 * @see get_post_type_object()
 *
 * @param string $post_type Post type name.
 * @return bool Whether post type is registered.
 */
function post_type_exists( $post_type ) {
	return (bool) get_post_type_object( $post_type );
}