2.1. Introduction

PHP borrows a bit of its syntax from other languages such as C, shell, Perl, and even Java. It is really a hybrid language, taking the best features from other languages and creating an easy-to-use and powerful scripting language.

When you finish reading this chapter, you will have learned

• The basic language structure of PHP

• How PHP is embedded in HTML

• How to write comments

• Managing variables and basic data types

• Defining constants for simple values

• The most common control structures, most of which are available in other programming languages

• Built-in or user-defined functions

If you are an experienced PHP 4 developer, you might want to skip to the next chapter, which covers object-oriented support of the language that has changed significantly in PHP 5.