Chapter 4. Working with Variables and Data

This chapter discusses data types and variables in JavaScript. After reading this chapter, you'll be able to

  • Understand the six different data types used in JavaScript.

  • Use functions associated with the six data types.

  • Create variables.

  • Define objects and arrays.

  • Understand the scope of variables.

  • Debug JavaScript with Firebug.

Data Types in JavaScript

The data types of a language describe the basic elements that can be used within that language. You're likely already familiar with data types from other languages, such as strings or integers. Depending upon whom you ask, JavaScript defines anywhere from three to six data types. You'll work with all these data types regularly, some more than others.

The six data ...

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