Run results for: for in Object.keys vs foreach Object.keys

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:109.0) Gecko/20100101 Firefox/113.0

Browser: Firefox 113

Operating system: Windows

Device Platform: Desktop

Date tested: one year ago

Test name	Executions per second
for in Object.keys	13.1 Ops/sec
foreach Object.keys	13.1 Ops/sec

Script Preparation code:

var obj = new Object()
var keys = (new Array(10000)).fill(0).map((x, i) => { return i + 1 })
keys.forEach((x) => { obj['prop' + x] = x })

Tests:

for in Object.keys
const keys = Object.keys(obj); for (let i = 0; i < keys.length; i += 1){ console.log(keys[i]); }
foreach Object.keys
Object.keys(obj).forEach(function(key) { console.log(key); });