Book Image

Object-Oriented JavaScript - Third Edition

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

Object-Oriented JavaScript - Third Edition

5 (1)
By: Ved Antani, Stoyan STEFANOV

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 (25 chapters)
Object-Oriented JavaScript - Third Edition
About the Authors
About the Reviewer
Customer Feedback
Built-in Functions
Regular Expressions

ES6 object methods

ES6 introduces a few static helper methods for objects. Object.assign is a helper method that replaces popular mixins to perform a shallow copy of an object.

Copy properties using Object.assign

This method is used to copy properties of the target object into the source object. In other words, this method merges the source object with the target object and modifies the target object:

    let a = {} 
    Object.assign(a, { age: 25 }) 
    console.log(a)  //{"age":25} 

The first parameter to Object.assign is the target on which source properties are copied. The same target object is returned to the caller. Existing properties are overwritten, while properties that aren't part of the source object are ignored:

    let a = {age : 23, gender: "male"} 
    Object.assign(a, { age: 25 })    // age overwritten, but gender ignored 
    console.log(a)  //{"age":25, "gender":"male"} 

Object.assign can take multiple source objects. You can write Object.assign...