Run results for: Object iteration benchmark

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/137.0.0.0 Safari/537.36

Browser: Chrome 137

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: one year ago

for of Object.keys()

540K/s

for with Object.keys()

524K/s

for in

317K/s

for in with Object.hasOwn()

266K/s

View exact numbers

Script Preparation code:

const o = {};

for (let i = 0; i < 36; i++) {
  o[i.toString(36)] = 0;
}

Tests:

for with Object.keys()
const ks = Object.keys(o); for (let i = 0, l = ks.length; i < l; i++) { o[ks[i]]++; }
for of Object.keys()
for (const k of Object.keys(o)) { o[k]++; }
for in with Object.hasOwn()
for (const k in o) { if (Object.hasOwn(o, k)) { o[k]++; } }
for in
for (const k in o) { o[k]++; }