This code returns a new array|object, only unique numbers.

Unique.js

const array = [1,1,2,3,4,5,5,5,6,7,8];
const array2 = new Set(array);
const uniq = [...new Set(array)];

//Unique Array
console.log('Unique array', uniq);
//Unique Object
console.log('Object', array2);