Benchmark: object.keys for loop vs for in

Script Preparation code:

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

Tests:

for-in
for (let i=10000; i > 0; i--) { const arr = []; for (const key in obj) { arr.push(key); } }
Object.keys() -> for-loop
for (let i=10000; i > 0; i--) { const keys = Object.keys(obj) for (let i=10000; i < keys.length; i--) { arr.push(keys[i]); }; }

Rendered benchmark preparation results:

Previous results

Test case name	Result
for-in
Object.keys() -> for-loop

Latest run results:

Run details: (Test run date: 8 months ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/142.0.0.0 Safari/537.36

Browser/OS: Chrome 142 on Mac OS X 10.15.7

Object.keys() -> for-loop

9K/s

for-in

5K/s

View exact numbers

Test name	Executions per second
✓ Object.keys() -> for-loop	8,840 Ops/sec
for-in	5,173 Ops/sec

object.keys for loop vs for in (version: 1)