Run results for: JavaScript Object.assign vs for in loop (-2)

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:129.0) Gecko/20100101 Firefox/129.0

Browser: Firefox 129

Operating system: Windows

Device Platform: Desktop

Date tested: one year ago

for in loop

7.4M/s

Object.assign

7.1M/s

View exact numbers

Test name	Executions per second
✓ for in loop	7,377,199 Ops/sec
Object.assign	7,095,090 Ops/sec

Tests:

Object.assign
const a = { x: 'xxx', y: 1, z: null } const b = { z: 1, u: 'uuu', v: { a: 9 } } Object.assign(a, b); Object.assign(b, a);
for in loop
const a = { x: 'xxx', y: 1, z: null } const b = { z: 1, u: 'uuu', v: { a: 9 } } for (let prop in b) a[prop] = b[prop]; for (let prop in a) b[prop] = a[prop];