Beyond Arrays and Objects: Exploring Sets and Maps in JavaScript

We all know the classic data structures in JavaScript: arrays for ordered lists and objects for key-value pairs. But what if you need to ensure unique values or want a more efficient way to search and retrieve data? That’s where Sets and Maps come in, offering unique capabilities beyond the usual suspects.

The Trouble with Arrays: Uniqueness and Searching

Imagine you’re building a shopping cart feature. You want to keep track of the items a user adds, but you don’t want duplicates. With a regular array, you’d have to manually check for existing items before adding new ones, making the code cumbersome and inefficient.

let cart = [];

function addItemToCart(item) {
  if (!cart.includes(item)) {
    cart.push(item);
  }
}

Sets: Ensuring Uniqueness with Elegance

Sets are like special arrays that only allow unique values. Adding a duplicate item has no effect.

Let’s rewrite our shopping cart example using a Set:

let cart = new Set();

function addItemToCart(item) {
  cart.add(item); // Duplicates are ignored automatically
}

Much cleaner, right? Sets also provide handy methods like has to check for…