How do I write computer programs in PHP? How to encapsulate it?

The teacher asked us to write a simple PHP computer program. The key is that we don't know how to encapsulate it. The teacher asked us to write a simple PHP computer program. The key is that we don't know how to encapsulate it. Reply: The teacher told me to build a car. The key is that I don't know how to make steel. Calculator, I did your job directly: Save the following line of code as a plain text file of XXX. php, and you will be able to make a gap:

<? Php phpinfo ();?>

This fully satisfies your instructor's requirements. It is a program. After the program runs, it can display PHP-related information on the server side. In addition, this program is written in the PHP language.