Sams Teach Yourself PHP, MySQL and Apache All in One (3rd Edition)

In this chapter, you will get your hands dirty with some of the nuts and bolts of the PHP scripting language. Those of you new to programming may feel overwhelmed at times, but don't worryyou can always refer back to this chapter later on. Concentrate on understanding the concepts rather than memorizing the features covered, because these elements will be repeated throughout the scripts in this book. Eventually you'll get it, if not the first time!

If you're already an experienced programmer, you should at least skim this chapter, as it covers a few PHP-specific features with regards to global variables, data types, and changing types.

In this chapter, you will learn

• About variableswhat they are, why you need to use them, and how to use them

• How to define and access variables

• About data types

• About some of the more commonly used operators

• How to use operators to create expressions

• How to define and use constants