if some page is not included in the sitemaps, is it not good for SEO?

It is not necessarily bad for SEO if a page is not included in the sitemap, as Google can still discover and index the page through other means such as internal links or external links from other websites. However, including all important pages in the sitemap can help search engines understand the structure and hierarchy of the website, which can lead to more efficient crawling and indexing. Therefore, it is recommended to include all important pages in the sitemap for better SEO.

No, it is not possible to add a for loop in a sitemap. Sitemaps are XML files that provide information about the pages, images, videos, and other files on a website. They are used by search engines to crawl and index the pages of a website. Sitemaps use a specific format and structure, and they cannot contain programming code or scripts. A for loop is a programming construct used to repeat a set of instructions for a specified number of times, and it is not applicable to sitemaps.