ES6 introduces many new features to embrace the developer as well as the browsers to perform in a optimal performant way.
Set
Set is new type of data structure that we can use to store Unique values which can be of any type but they must all be uniqie.
Create a Set
To create a set we use Set constructor var mySet = new Set();
Add Values to set
let myArray = [1, 4, 1, 5, 5, 7, 8, 9, 0, 0]
let mySet = new Set(myArray)
Now if you do a console.log(mySet); you will see
Set {1, 4, 5, 7, 8, 9, 0}
Map
Map is similar to Set but it manges key-value pair instead of individual values.
Create a Map
var myMap = new Map(); will create an instance of Map and to add values to it we can do let
myOtherMap = new Map([['a', 2], [1, 'b']])
console.log(myOtherMap); will show Map {"a" => 2, 1 => "b"}
WeakSet and WeakMap
Similar to regular Map and Set but the difference is that the object references inside them are held weakly. So it wont prevent garbage collection.