Core PHP Programming, Third Edition

Chapter 2. Variables, Operators, and Expressions

Topics in This Chapter

• A Top-Down View

• Data Types

• Variables

• Constants

• Operators

• Building Expressions

This chapter discusses fundamental building blocks of PHP scripts: variables, operators, expressions, and statements. A statement is a piece of code that instructs PHP to do something. For instance, a statement may compute a value and store it in memory, it may print something, or it may save something to the disk. There are many different types of statements in PHP. Function calls, variable assignments, loops, and if conditions are all statements.

Although the description of identifiers, expressions, and statements may seem simplistic, they are important building blocks that allow you to understand ...