April 25, 2023

What is the Difference Between Map and Set in Javascript

By Krishnaa JavaScript Questions 0 Comments

As a web developer, it’s essential to know the different data structures available in JavaScript. Two commonly used data structures are Map and Set. While they may seem similar at first, they have distinct characteristics and are used for different purposes. In this tutorial, we will explore the differences between Map and Set in JavaScript.

Map

A Map is a collection of key-value pairs where each key can map to only one value. In other words, a key in a Map can only exist once. You can think of it like a real-world map where each location has a unique name, and that name corresponds to a particular location. The syntax for creating a Map in JavaScript is as follows:

const map = new Map();

To add a key-value pair to a Map, you can use the set() method:

map.set("key", "value");

To retrieve a value from a Map, you can use the get() method:

map.get("key"); // returns "value"

To check if a Map contains a particular key, you can use the has() method:

map.has("key"); // returns true

Set

A Set is a collection of unique values, where each value can only exist once. You can think of it like a real-world set where each element can only exist once. The syntax for creating a Set in JavaScript is as follows:

const set = new Set();

To add a value to a Set, you can use the add() method:

set.add("value");

To check if a Set contains a particular value, you can use the has() method:

set.has("value"); // returns true

To remove a value from a Set, you can use the delete() method:

set.delete("value");

Differences Between Map and Set

While Map and Set are both collections of unique elements, they have different use cases. Here are some of the differences between Map and Set:

Map is used to store key-value pairs, whereas Set is used to store unique values.
In a Map, each key can only map to one value, whereas in a Set, each value can only exist once.
Map allows you to retrieve a value using its corresponding key, whereas in Set, you cannot retrieve a value based on its position or index.
Map is iterable in the order of insertion, whereas Set is iterable in the order of the elements’ values.

In this tutorial, we explored the differences between Map and Set in JavaScript. While they may seem similar, they have different use cases and should be used accordingly. Understanding these data structures is essential for writing efficient and effective code in JavaScript. By implementing them correctly, you can improve the performance and readability of your code.

Map

Set

Differences Between Map and Set

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