You’ve got a couple of PHP programs running, and one of them even works with an HTML form. But so far, you’ve just been typing code. Even though you’ve just gotten started with PHP, you’re ready to dig deeper, and start to understand what’s going on in that code. In this chapter, you’re going to get comfortable with a lot of the PHP syntax: that means learning what special words you type into your programs, and what each one of those special words—usually called keywords—tells PHP to do.

Fortunately, this learning doesn’t mean you can’t still build interesting programs that run in a web browser. In fact, since almost everything that’s done with PHP involves Web pages, all your scripts in this chapter will accept information from a Web form and work with that information. So you’re not just learning PHP; you’re learning to write Web applications.