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Object-Oriented JavaScript - Second Edition

You're reading from   Object-Oriented JavaScript - Second Edition If you've limited or no experience with JavaScript, this book will put you on the road to being an expert. A wonderfully compiled introduction to objects in JavaScript, it teaches through examples and practical play.

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Product type Paperback
Published in Jul 2013
Publisher Packt
ISBN-13 9781849693127
Length 382 pages
Edition 2nd Edition
Languages
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Toc

Table of Contents (14) Chapters Close

Preface 1. Object-oriented JavaScript FREE CHAPTER 2. Primitive Data Types, Arrays, Loops, and Conditions 3. Functions 4. Objects 5. Prototype 6. Inheritance 7. The Browser Environment 8. Coding and Design Patterns A. Reserved Words B. Built-in Functions
C. Built-in Objects D. Regular Expressions
Index

object()


Based on the idea that objects inherit from objects, Douglas Crockford advocates the use of an object() function that accepts an object and returns a new one that has the parent as a prototype.

function object(o) {
function F() {}
F.prototype = o;
return new F();
}

If you need access to an uber property, you can modify the object() function like so:

function object(o) {
var n;
function F() {}
F.prototype = o;
n = new F();
n.uber = o;
return n;
}

Using this function is the same as using the extendCopy(): you take an object such as twoDee, create a new object from it and then proceed to augmenting the new object.

var triangle = object(twoDee);
triangle.name = 'Triangle';
triangle.getArea = function () {
return this.side * this.height / 2;
};

The new triangle still behaves the same way:

>triangle.toString();
"Shape, 2D shape, Triangle"

This pattern is also referred to as prototypal inheritance , because you use a parent object as the prototype of a child object. It's also adopted and built...

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