How JavaScript Works: Master the Basics of JavaScript and Modern Web App Development

© The Author(s), under exclusive license to APress Media, LLC, part of Springer Nature 2023

J. SimpsonHow JavaScript Works https://doi.org/10.1007/978-1-4842-9738-4_9

9. Maps and Sets

Jonathon Simpson¹  

(1)

Belfast, Antrim, UK

 

While objects and arrays are the most common way of storing data in JavaScript, they do have some limitations. For example, neither objects nor arrays have the ability to create a unique list without duplicates. Similarly, objects cannot contain keys that are not strings or symbols. To overcome these challenges and more, two additional special types of objects exist known as maps and sets. Both of these have unique functionality, which makes them well-suited to certain tasks. In this chapter, we’ll be diving into both of these ...