Run results for: Lodash _.union vs native Set() vs Concat & filter

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:81.0) Gecko/20100101 Firefox/81.0

Browser: Firefox 81

Operating system: Windows

Device Platform: Desktop

Date tested: 4 years ago

Test name	Executions per second
_.union	2938319.5 Ops/sec
Set()	1448019.9 Ops/sec
Set() convert back to array	1081264.9 Ops/sec
Concat & Filter	4203871.0 Ops/sec

HTML Preparation code:

<script type="text/javascript" src="https://cdn.jsdelivr.net/npm/lodash@4.17.10/lodash.min.js"></script>

Script Preparation code:

var a = [1, 2, 3, 4, 5]
var b = [3, 4, 5, 6, 7]
Array.prototype.cfunion = function (array) {
  var conc = this.concat(array);
  return conc.filter((i,p)=>{
    return conc.indexOf(i) == p
  });
};

Tests:

_.union
var c = _.union(a, b)
Set()
var c = new Set(a, b)
Set() convert back to array
var c = new Set(a, b) var d = Array.from(c)
Concat & Filter
var c = a.cfunion(b)

Run results for: Lodash _.union vs native Set() vs Concat & filter

_.union

Set()

Set() convert back to array

Concat & Filter