Chapter 4. Variables, Operators, Data Types, and File Inclusion

This chapter examines how you define, declare, assign, compare, and process variables. It covers the following topics:

  • Variables

    • User-defined variables

    • Operators

    • Data types

    • Global variables

    • Predefined variables

  • Library file inclusion

  • Reserved words and system constants

By the end of this chapter, you will understand how variables, operators, and data types work. You will also understand how to define global variables and be aware of the predefined variables available in PHP. At the end of the chapter you will find a list of reserved words and a tool to find your defined environment constants.

The chapter sections are organized sequentially and assume you have read the prior sections. Before ...

Get Oracle Database 10g Express Edition PHP Web Programming now with the O’Reilly learning platform.

O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.