Book Image

Learning JavaScript Data Structures and Algorithms - Third Edition

Book Image

Learning JavaScript Data Structures and Algorithms - Third Edition

Overview of this book

A data structure is a particular way of organizing data in a computer to utilize resources efficiently. Data structures and algorithms are the base of every solution to any programming problem. With this book, you will learn to write complex and powerful code using the latest ES 2017 features. Learning JavaScript Data Structures and Algorithms begins by covering the basics of JavaScript and introduces you to ECMAScript 2017, before gradually moving on to the most important data structures such as arrays, queues, stacks, and linked lists. You will gain in-depth knowledge of how hash tables and set data structures function as well as how trees and hash maps can be used to search files in an HD or represent a database. This book serves as a route to take you deeper into JavaScript. You’ll also get a greater understanding of why and how graphs, one of the most complex data structures, are largely used in GPS navigation systems in social networks. Toward the end of the book, you’ll discover how all the theories presented in this book can be applied to solve real-world problems while working on your own computer networks and Facebook searches.
Table of Contents (22 chapters)
Title Page
Dedication
Packt Upsell
Contributors
Preface
Index

Searching algorithms


Now, let's talk about searching algorithms. If we take a look at the algorithms we implemented in previous chapters, such as the search method of the BinarySearchTree class (Chapter 10, Trees) or the indexOf method of the LinkedList class (Chapter 6, Linked Lists), these are all search algorithms, and of course, each one was implemented according to the behavior of its data structure. So we are already familiar with two search algorithms; we just do not know their "official" names yet!

The sequential search

The sequential search or linear search is the most basic search algorithm. It consists of comparing each element of the data structure with the one we are looking for. It is also the most inefficient one.

Let's take a look at its implementation:

const DOES_NOT_EXIST = -1;

function sequentialSearch(array, value, equalsFn = defaultEquals) {
  for (let i = 0; i < array.length; i++) { // {1}
    if (equalsFn(value, array[i])) { // {2}
      return i; // {3}
    }
  }...