Book Image

Learning JavaScript Data Structures and Algorithms - Second Edition

By : Loiane Groner
Book Image

Learning JavaScript Data Structures and Algorithms - Second Edition

By: Loiane Groner

Overview of this book

This book begins by covering basics of the JavaScript language and introducing ECMAScript 7, before gradually moving on to the current implementations of ECMAScript 6. You will gain an in-depth knowledge of how hash tables and set data structure functions, as well as how trees and hash maps can be used to search files in a HD or represent a database. This book is an accessible route deeper into JavaScript. Graphs being one of the most complex data structures you’ll encounter, we’ll also give you a better understanding of why and how graphs are largely used in GPS navigation systems in social networks. Toward the end of the book, you’ll discover how all the theories presented by this book can be applied in real-world solutions while working on your own computer networks and Facebook searches.
Table of Contents (18 chapters)
Learning JavaScript Data Structures and Algorithms - Second Edition
Credits
About the Author
About the Reviewer
www.PacktPub.com
Preface

The ES6 Map class


ECMAScript 2015 introduced a Map class as part of the JavaScript API. We developed our Dictionary class based on the ES6  Map class.

Note

You can take a look at the details of the ECMAScript 6 Map class implementation at https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Map (or http://goo.gl/dm8VP6 ).

Now, let's consider how we can use the native Map class, as well.

Let's use the same examples we used to test our Dictionary class:

var map = new Map(); 
 
map.set('Gandalf', '[email protected]'); 
map.set('John', '[email protected]'); 
map.set('Tyrion', '[email protected]'); 
 
console.log(map.has('Gandalf'));   //outputs true 
console.log(map.size);   //outputs 3 
console.log(map.keys()); //outputs ["Gandalf", "John", "Tyrion"] 
console.log(map.values()); //outputs ["[email protected]", "[email protected]", "[email protected]"] 
console.log(map.get('Tyrion')); //outputs [email protected] 

The difference between our Dictionary class and the ES6...