To find the HTML code, you need to have the Web page open in your browser. Go to "Tools," select "Web Developer" and click "Page Source" in Mozilla Firefox to see your Facebook HTML.

You should not use an interface if you need to write the same code for the interface methods. In this case, you should use an abstract class, define the method once, and reuse it as needed.

To work with the code examples provided in this article, you should have Visual Studio 2019 installed in your system. If you don’t already have a copy, you can download Visual Studio 2019 here.