Run results for: Cost of adding and removing event listeners

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/143.0.0.0 Safari/537.36 Edg/143.0.0.0

Browser: Chrome 143

Operating system: Windows

Device Platform: Desktop

Date tested: 7 months ago

Assigning once

599K/s

Assigning 1000

657/s

View exact numbers

Test name	Executions per second
✓ Assigning once	599,395 Ops/sec
Assigning 1000	657 Ops/sec

HTML Preparation code:

<!--your preparation HTML code goes here-->

Script Preparation code:

const callbacks = Array.from({ length: 1000 }, () => () => {})
const callback = () => {}

function useEffectCallback(callback) {
  window.addEventListener('keydown', callback);
  window.removeEventListener('keydown', callback);
}

Tests:

Assigning once
useEffectCallback(callback)
Assigning 1000
callbacks.forEach(callback => useEffectCallback(callback))