JavaScript Cookbook, 2nd Edition

Chapter 4. The Malleable JavaScript Object

With the increased interest in functional programming, you might think there’s less interest in JavaScript’s object-based capability. However, JavaScript is a flexible, adaptable language, and is just as happy to embrace both functional programming and object-oriented development.

There is a caveat related to JavaScript’s object-oriented capabilities: unlike languages such as Java or C++, which are based on classes and class instances, JavaScript is based on prototypical inheritance. What prototypical inheritance means is that reuse occurs through creating new instances of existing objects, rather than instances of a class. Instead of extensibility occurring through class inheritance, prototypical extensibility happens by enhancing an existing object with new properties and methods.

Prototype-based languages have an advantage in that you don’t have to worry about creating the classes first, and then the applications. You can focus on creating applications, and then deriving the object framework via the effort.

It sounds like a mishmash concept, but hopefully as you walk through the recipes you’ll get a better feel for JavaScript’s prototype-based, object-oriented capabilities.

A Brief Note About Functional Programming and Object-Oriented Development

In the last few years, especially after the explosive growth of jQuery and Node.js, the trend is to use functional programming (discussed in Chapter 2) as a development approach over the more traditional ...