Benchmark: Object key, typeof === 'function' vs startsWith 'on' vs 'o' 'n'

HTML Preparation code:

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

Script Preparation code:

const attrs = {
  class: 'test',
  onclick: e => console.log(e),
  style: 'color: red;',
  onfocus: e => console.log(e),
};
const count = 1000;

Tests:

typeof key === function
for(let i = 0; i < count; i++) { const el = document.createElement('div'); for(const [k, v] of Object.entries(attrs)) { if(typeof k === 'function') el[k] = v; else el.setAttribute(k, v); } }
startsWith on
for(let i = 0; i < count; i++) { const el = document.createElement('div'); for(const [k, v] of Object.entries(attrs)) { if(k.startsWith('on')) el[k] = v; else el.setAttribute(k, v); } }
0 === o and 1 === n
for(let i = 0; i < count; i++) { const el = document.createElement('div'); for(const [k, v] of Object.entries(attrs)) { if(k[0] === 'o' && k[1] === 'n') el[k] = v; else el.setAttribute(k, v); } }

Rendered benchmark preparation results:

Previous results

Latest run results:

Run details: (Test run date: 10 months ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:128.0) Gecko/20100101 Firefox/128.0

Browser/OS: Firefox 128 on Windows

0 === o and 1 === n

232/s

startsWith on

218/s

typeof key === function

175/s

View exact numbers

Object key, typeof === 'function' vs startsWith 'on' vs 'o' 'n' (version: 1)