Is it a good practice to use includes code in your php site? Can search engine read those links inside includes?
Yup - include files in php or asp are fine (actually a very good idea if you to make changes across multiple pages easily). The pages are compiled on the server before the crawlers get to "read" them so the included content is rendered as a part of the page being spidered - unlike frames, iframes or shared borders which should be avoided.
Yes include code is good for your site & whatever is present in the include file if in html form would be indexable by search engines.
Since all the search engines will ever see is the HTML output, using PHP and/or server-side includes is fine.
should be ok.. and after google crawl it you can try visit the cache site to see either its being crawl
Thank you all for your reply. But my file extension is in .php. I'm still on the process of making my on cms. I used includes for fast editing of the page footer and the navigation on the side of my page.
It does not matter what the file extension is. PHP is server side technology. By the time the user agent sees it (whether a browser or a bot) it will be presented as html markup.
As Willybfriendly said, it doesn't matter if the file extension is .html .php .aspx or .mydoglarry (okay, I made that last one up). All the search engine will see is what you see in the browser when you click "View Source". And that's HTML (along with any CSS or JavaScript embedded in the HTML file).