If you need to ensure full compatibility with Navigator 2 users, it's best to avoid this feature of JavaScript. Array lengths in JavaScript aren't fixed, but can be increased dynamically by simply assigning values to new array entries, in much the same way that you dynamically added properties to an instance of an object earlier in this chapter. In the previous example, for instance, you created a three-element array of a string, an integer, and a Boolean value, respectively. In this chapter, you took a close look at objects, the building blocks on which JavaScript is built. Sets of pre-defined objects are what give both client and server JavaScript their capabilities.
Objects define groups of information and methods for working with that information.
As a programmer, you can extend JavaScript by creating objects with their own properties and methods. Finally, you learned about arrays and their relationship with the JavaScript object model. As a unique type of object, arrays share many of the features of objects and have a flexibility not found in many other languages. In the next chapter, you'll move on to explore the main objects and functions of client JavaScript.