Map and Set in JavaScript
Map and Set are the modern feauture of JavaScript comes in ES6
What is map ?
Map is a collection of key-value pairs just like objects but it has some special powers that made it more powerful and useful than the objects
It is a built-in Data Structure in JavaScript
const map = new Map();
map.set("fname", "Prashant");
map.set("lname", "Chandel");
map.set("role", "developer");
console.log(map.get("name")); // "Nawazish"
console.log(map.size); // 3
Map methods
.set()
map.set() allows you to insert values in map, It takes two arguments one is key and the other one is value
const map = new Map();
map.set("name", "Prashant");
console.log(map.get("name"));
.get()
map.get() is used to take value from the map
const map = new Map();
map.set("name", "Prashant");
console.log(map.get("name"));
.size
map.size is the property that tell us about the total size of key-value pairs
const map = new Map();
map.set("fname", "Prashant");
map.set("lname", "Chandel");
map.set("role", "developer");
console.log(map.get("name")); // "Nawazish"
console.log(map.size); // 3
Defference Between map and Object
What is Set ?
set let you store unique values weather they are primitive or non-primitive datatypes, These are same as in maths we have sets
const strongest = new Set();
strongest.add("Son Goku");
strongest.add("Saitama");
strongest.add("Alien X");
console.log(strongest.has("Son Goku")); // true
console.log(strongest.size); // 3
Some Basic methods of set
.add()
used to insert a value in set
strongest.add("Son Goku");
.has()
it checks weather a value is present in the set or not, it returns a boolean
const strongest = new Set();
strongest.add("Son Goku");
strongest.add("Saitama");
strongest.add("Alien X");
console.log(strongest.has("Son Goku"));
.size
It is same as the size in the map,Here it tells that how many elements are there in a set
const strongest = new Set();
strongest.add("Son Goku");
strongest.add("Saitama");
strongest.add("Alien X");
console.log(strongest.has("Son Goku")); // true
console.log(strongest.size); // 3
Difference Between Sets and Array
When to use Map and Set
Map:
When insertion & deletion is the priority
It is also used to make In-Memory DB
Set:
It is used when we don't want to store duplicate values
Also by this we can use hash-based lookup
Conclusion:
In summary, Both Set and Map are the upgraded version of Array and Objects
It depends upon our usecase when we use map or object.