Run results for: for-in iteration with and without cache

Run details:

User agent: Mozilla/5.0 (Windows NT 6.3; Win64; x64; rv:67.0) Gecko/20100101 Firefox/67.0

Browser: Firefox 67

Operating system: Windows 8.1

Device Platform: Desktop

Date tested: 5 years ago

Test name	Executions per second
No cache	1.8 Ops/sec
Cache	1.9 Ops/sec

Tests:

No cache
const object = {}; for (let i = 0; i < 1000000; i++) { object[i] = i; } for (const key in Object.keys(object)) { object[key]++; }
Cache
const object = {}; for (let i = 0; i < 1000000; i++) { object[i] = i; } const keys = Object.keys(object); for (const key in keys) { object[key]++; }