JavaScript All-in-One For Dummies

Chapter 7

Making and Using Objects

IN THIS CHAPTER

Creating, modifying, comparing, and copying objects

Introducing prototypes

Deleting object properties

“You can find the entire cosmos lurking in its least remarkable objects.”

—WISLAWA SZYMBORSKA

Data is rarely as simple as it seems. To understand any concept or physical object often requires multiple data points. A full description of a toaster, for example, would include its size, color, and power requirements as well as a description of what it does. None of the data types I describe earlier in this book can be used to describe a toaster by themselves, but in combination, they can.

Objects: The Basics

Objects are reusable components that contain data and functionality. Objects in real life have characteristics that define what they are. For example, a pencil has a length, a diameter, a color, and other characteristics that describe it. A pencil also has things you can do with it, such as write, erase, sharpen, and break.

In JavaScript, both the data and functionality encapsulated by an object are called properties. If a property has a function value, it's also known as a method. JavaScript objects can be used to describe physical ...