December 2012
Beginner
164 pages
3h 15m
English
Content preview from JavaScript Enlightenment
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Chapter 1. JavaScript Objects
Creating Objects
In JavaScript, objects are king: Almost everything is an object or acts like an object. Understand objects and you will understand JavaScript. So let’s examine the creation of objects in JavaScript.
An object is just a container for a collection of named values (a.k.a. properties). Before we look at any JavaScript code, let’s first reason this out. Take myself, for example. Using plain language, we can express in a table, a “cody”:
cody | |
property: | property value: |
living | true |
age | 33 |
gender | male |
The word “cody” in the table above is just a label for the group of property names and corresponding values that make up exactly what a cody is. As you can see from the table, I am living, 33, and a male.
JavaScript, however, does not speak in tables. It speaks in objects, which are not unlike the parts contained in the “cody” table. Translating the above table into an actual JavaScript object would look like this:
<!DOCTYPE html><html lang="en"><body><script> // create the cody object... var cody = new Object(); // then fill the cody object with properties (using dot notation) cody.living = true; cody.age = 33; cody.gender = 'male'; console.log(cody); // logs Object {living = true, age = 33, gender = 'male'} </script></body></html>
Keep this at the forefront of your mind: objects are really just containers for properties, each of which has a name and a value. This notion of a container of properties with named values (i.e., an object) is used by JavaScript ...
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I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.