JavaScript® Bible, Sixth Edition

Chapter 13. JavaScript Essentials

IN THIS CHAPTER

• JavaScript language versions

• How to separate the language from the document object model

• Where scripts go in your documents

• Language highlights for experienced programmers

Whenever JavaScript is discussed in the context of the web browser environment, it is sometimes difficult to distinguish between JavaScript the scripting language and the objects that you use the language to control. Even so, it's important to separate the language from the object model just enough to help you make important design decisions when considering JavaScript-enhanced pages. You may come to appreciate the separation in the future if you use JavaScript for other object models, such as server-side programming or scripting Flash animations. All the basics of the language are identical. Only the objects differ.

This chapter elaborates on many of the fundamental subjects about the core JavaScript language raised throughout the tutorial (Part II), particularly as they relate to deploying scripts in a world in which visitors to your pages may use a wide variety of browsers. Along the way, you receive additional insights into the language itself. Fortunately, browser differences as they apply to JavaScript have lessened considerably as modern browsers continue to inch closer to consistently supporting the JavaScript (ECMAScript) standard. You can find details about the JavaScript core language syntax in Part IV.

JavaScript Versions

The JavaScript language has its own ...