Have anybody observed full URL's in source code. e.g. In some website's source code you will find only index.html but in some website's source code you will find full URL instead of only file names like www.example.com/index.html or only www.example.com instead of index.html So my question is using full URL while coding is useful for SEO or not? Pardon my English. But understand the issue and give your views.
obviously you should use www.example.com, not the domain.com/index.html and you should do 301 redirct to www.example.com
I'm always use full url in code. At first: no chance make mistake via search engines how indexing your page. At second, from my experience its a bit better in seo, working more like external backlinks. From few years, when I am using this type of url's at all my my domains, have no one incident with search engines.
your home page can have many different types of extensions website.com website.com/index.htm website.com/home.htm and so on look into canonization
i dont thing it really does make much difference. however some people would prefer putting the whole url, they think its better.
Plus, depending on the server, os, versions, features.. it may reference server locations differently. Some need the full file path and a lot of common ones do not.
Only main root URL is good. No need to add index.html or index.php.. It will cause canonical problem.
Complete url protects you from many complexities while working or in future work. It depends upon you which way you choose. I am always found of giving full url in my codings