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

Using a mix of prototypal inheritance and copying properties


When you use inheritance, you will most likely want to take an already existing functionality and then build upon it. This means creating a new object by inheriting from an existing object and then adding additional methods and properties. You can do this with one function call using a combination of the last two approaches just discussed.

You can:

  • Use prototypal inheritance to use an existing object as a prototype of a new one

  • Copy all the properties of another object into the newly created one:

        function objectPlus(o, stuff) { 
          var n; 
          function F() {} 
          F.prototype = o; 
          n = new F(); 
          n.uber = o; 
       
         for (var i in stuff) { 
            n[i] = stuff[i]; 
            } 
          return n; 
        } 
    

This function takes an object o to inherit from and another object stuff that has the additional methods and properties that are to be copied. Let's see...