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

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/18.0.1 Safari/605.1.15

Browser: Safari 18

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: one year ago

Benchmark engine: Benchmark.js

Concat & Filter

8.8M/s

Set()

7.1M/s

_.union

5.0M/s

Set() convert back to array

4.6M/s

View exact numbers

Test name	Executions per second
✓ Concat & Filter	8,762,077 Ops/sec
Set()	7,146,668 Ops/sec
_.union	4,968,239 Ops/sec
Set() convert back to array	4,612,684 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)