Remove Duplicate Items in an Array

The Set object in JavaScript is a collection of unique values. It can be used to store and manipulate a collection of primitive values (such as strings or numbers) or object references. We can use this to remove all repeat values from an array by initializing the Set object with an array as an argument. This will create a Set object, the next step to convert it back to an array is to use the spread operator to spread the object into an array

Example

let array1 = [1,1,2,2,3,3,4,4];
let array2 = [...new Set(array1)];