Run results for: Set union methods

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/115.0.0.0 Safari/537.36

Browser: Chrome 115

Operating system: Windows

Device Platform: Desktop

Date tested: one year ago

Test name	Executions per second
Spreading	15187.5 Ops/sec
Set.forEach + Set.add	13732.4 Ops/sec
Generators	9667.0 Ops/sec

HTML Preparation code:

<script src="https://cdnjs.cloudflare.com/ajax/libs/nanoid/4.0.1/index.browser.js" integrity="sha512-YFaQHp+hWX9CMeIMngYK23kSIWaYlgsswmzmIdEw/HcK/5NLhXY2MbT0wQB5DnUzjW1uky4quIHtksukqZGkMw==" crossorigin="anonymous" referrerpolicy="no-referrer"></script>

Script Preparation code:

const SET_SIZE = 1000;

var set1 = new Set()
var set2 = new Set()
while (i < SET_SIZE) {
    const nid = 'key:'+Math.random();
    set1.add(nid);
    if (i % 2 == 0) set2.add(nid);
    i++;
}
while (i < SET_SIZE / 2) {
    set2.add('key:'+Math.random());
}

Tests:

Spreading
const set3 = new Set([...set1, ...set2]); console.log(set3.size)
Set.forEach + Set.add
const set3 = new Set(set1); set2.forEach(el => set3.add(el)); console.log(set3.size)
Generators
const set3 = new Set(function*() { yield* set1; yield* set2; }()); console.log(set3.size)

Run results for: Set union methods

Different ways to union JS Sets

Spreading

Set.forEach + Set.add

Generators