Run results for: for...in vs map

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/114.0.0.0 Safari/537.36

Browser: Chrome 114

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: one year ago

Test name	Executions per second
for...in	30715118.0 Ops/sec
map	7153077.5 Ops/sec

Tests:

for...in
const obj = { a: 'a', b: 'b', c: 'c', d: 'd', e: 'e', f: 'f' } const mapped = [] for (const key in obj) { mapped.push({ key: key, val: obj[key] }) }
map
const obj = { a: 'a', b: 'b', c: 'c', d: 'd', e: 'e', f: 'f' } const mapped = Object.keys(obj).map((key) => ({ key: key, val: obj[key] }))