JavaScript® Bible, Seventh Edition

Chapter 8. Programming Fundamentals, Part I

IN THIS CHAPTER

• What variables are and how to use them

• Why you must learn how to evaluate expressions

• How to convert data from one type to another

• How to use basic operators

The tutorial breaks away from HTML and documents for a while, as you begin to learn programming fundamentals that apply to practically every scripting and programming language you will encounter. Here, you start learning about variables, expressions, data types, and operators—things that might sound scary if you haven't programmed before. Don't worry. With a little practice, you will become quite comfortable with these terms and concepts.

What Language Is This?

The language you're studying is called JavaScript. But the language has some other names that you may have heard. JScript is Microsoft's name for the language. By leaving out the ava, the company doesn't have to license the Java name from its trademark owner: Sun Microsystems.

A standards body called ECMA (pronounced "ECK-ma") now governs the specifications for the language (no matter what you call it). The document that provides all of the details about the language is known as ECMA-262 (it's the 262nd standard published by ECMA). Both JavaScript and JScript are ECMA-262 compatible. Some earlier browser versions exhibit very slight deviations from ECMA-262 (which came later than the earliest browsers). The most serious discrepancies are noted in the core language reference in Part III of this book.

Working with Information ...