Learning JavaScript

Chapter 4. The JavaScript Objects

It might seem when looking at JavaScript examples that there are a great number of JavaScript objects. However, what you’re really seeing are objects from four different domains:

Those built into JavaScript

Those from the Browser Object Model

Those from the Document Object Model

Custom objects from the developer

The JavaScript objects are those that are built into JavaScript as language-specific components regardless of the agent that implements the language engine. As such, they’ll always be available, whether JavaScript is implemented in a traditional web browser or in a cell-phone interface.

Among these basic JavaScript objects are those that parallel our data types, discussed in Chapter 2: String for strings, Boolean for booleans, and, of course, Number for numbers. Each of these objects encapsulates our basic types; they manage conversion tasks, as well as provide additional functionality.

There are also several special-purpose objects, such as Math, Date, and RegExp. That last object provides regular-expression functionality to JavaScript. Regular expressions are powerful, though extremely cryptic, patterning capabilities that enable you to add very precise string matching to applications.

JavaScript also has one built-in aggregator object, the Array. All objects in JavaScript are inherently arrays, though they may not look as such when you work with them. All of these basic JavaScript objects are covered in this chapter.

The Object Constructor

Each ...