Run results for: for-in vs for of vs object.keys vs object.entries

Run details:

User agent: Mozilla/5.0 (Linux; arm_64; Android 14; ASUS_AI2202) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/124.0.6367.26 YaBrowser/24.6.6.26.00 SA/3 Mobile Safari/537.36

Browser: Yandex Browser 24

Operating system: Android

Device Platform: Mobile

Date tested: 2 years ago

for of - Object.entries

3.1M/s

for-in

1.4M/s

for of - Object.keys

1.2M/s

Object.keys - for loop

1.2M/s

Object.keys - forEach

947K/s

View exact numbers

Test name	Executions per second
✓ for of - Object.entries	3,091,272 Ops/sec
for-in	1,448,437 Ops/sec
for of - Object.keys	1,180,369 Ops/sec
Object.keys - for loop	1,173,527 Ops/sec
Object.keys - forEach	947,040 Ops/sec

Script Preparation code:

var obj = {
  'a': 1,
  'b': 1,
  'c': 1,
  'd': 1,
  'e': 1,
  'f': 1,
  'g': 1
};

Tests:

for-in
let result; for (var key in obj) { result += obj[key]; }
Object.keys - forEach
let result; Object.keys(obj).forEach(key => { result += obj[key]; });
Object.keys - for loop
let result; const keys = Object.keys(obj); for (let i = 0; i < keys.length; i++) { result += obj[keys[i]]; }
for of - Object.keys
let result; for (const key of Object.keys(obj)) { result += obj[key]; }
for of - Object.entries
let result; for (const [key, value] of Object.entries(obj)) { result += value; }