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Learning JavaScript Data Structures and Algorithms

You're reading from   Learning JavaScript Data Structures and Algorithms Enhance your problem-solving skills in JavaScript and TypeScript

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Product type Paperback
Published in Sep 2026
Publisher Packt
ISBN-13 9781836205395
Length 615 pages
Edition 4th Edition
Languages
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Author (1):
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Loiane Groner Loiane Groner
Author Profile Icon Loiane Groner
Loiane Groner
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Table of Contents (9) Chapters Close

Learning JavaScript Data Structures and Algorithms, Fourth Edition: Enhance your problem-solving skills in JavaScript and TypeScript
1 Introducing Data Structures and Algorithms in JavaScript FREE CHAPTER 2 Big O notation 3 Arrays 4 Stacks 5 Queues and Deques 6 Linked Lists 7 Sets 8 Dictionaries and Hashes

Searching an array

The JavaScript API provides a few different methods we can use to search or find elements in an array. Although we will learn how to re-create classic algorithms to search elements in Chapter 15, Searching and Shuffling Algorithms, it is always good to know we can use existing APIs without having to write the code ourselves.

Let's take a look at the existing JavaScript methods that allows us to search elements in an array.

Searching with indexOf, lastIndexOf and includes methods

The methods indexOf, lastIndexOf and includes have a very similar sintax as follows:

  • indexOf(element, fromIndex): searches for the element starting from the index fromIndex, and in case the element exists, returns its index, otherwise returns the value -1.
  • includes(element, fromIndex): searches for the element starting from the index fromIndex, and in case the element exists, returns true, otherwise returns false.

If we try to search for a number in our numbers array, let's check...

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