Book Image

Object-Oriented JavaScript - Third Edition

By : Stoyan STEFANOV, Antani
5 (1)
Book Image

Object-Oriented JavaScript - Third Edition

5 (1)
By: Stoyan STEFANOV, Antani

Overview of this book

JavaScript is an object-oriented programming language that is used for website development. Web pages developed today currently follow a paradigm that has three clearly distinguishable parts: content (HTML), presentation (CSS), and behavior (JavaScript). JavaScript is one important pillar in this paradigm, and is responsible for the running of the web pages. This book will take your JavaScript skills to a new level of sophistication and get you prepared for your journey through professional web development. Updated for ES6, this book covers everything you will need to unleash the power of object-oriented programming in JavaScript while building professional web applications. The book begins with the basics of object-oriented programming in JavaScript and then gradually progresses to cover functions, objects, and prototypes, and how these concepts can be used to make your programs cleaner, more maintainable, faster, and compatible with other programs/libraries. By the end of the book, you will have learned how to incorporate object-oriented programming in your web development workflow to build professional JavaScript applications.
Table of Contents (19 chapters)
15
B. Built-in Functions
17
D. Regular Expressions

Isolating the inheritance part into a function


Let's move the code that takes care of all the inheritance details from the last example into a reusable extend() function:

    function extend(Child, Parent) { 
    var F = function () {}; 
    F.prototype = Parent.prototype; 
    Child.prototype = new F(); 
    Child.prototype.constructor = Child; 
    Child.uber = Parent.prototype; 
    } 

Using this function (or your own custom version of it) helps you keep your code clean with regard to the repetitive inheritance-related tasks. This way, you can inherit by simply using the following two lines of code:

    extend(TwoDShape, Shape); 
    extend(Triangle, TwoDShape); 

Let's see a complete example:

    // inheritance helper 
    function extend(Child, Parent) { 
      var F = function () {}; 
      F.prototype = Parent.prototype; 
      Child.prototype = new F(); 
      Child.prototype.constructor = Child; 
      Child...