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/134.0.0.0 Safari/537.36

Browser: Chrome 134

Operating system: Windows

Device Platform: Desktop

Date tested: one year ago

Test name	Executions per second
Assigning once	1795471.5 Ops/sec
Assigning 1000	1902.2 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))

Run results for: Cost of adding and removing event listeners

Assigning once

Assigning 1000