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

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.14; rv:65.0) Gecko/20100101 Firefox/65.0

Browser: Firefox 65

Operating system: Mac OS X 10.14

Device Platform: Desktop

Date tested: 5 years ago

Test name	Executions per second
No cache	3.6 Ops/sec
Cache	3.7 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]++; }