Run results for: JavaScript spread operator vs Object.assign performance to merge into new object

Run details:

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 17_3_1 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/17.3.1 Mobile/15E148 Safari/604.1

Browser: Mobile Safari 17

Operating system: iOS 17.3.1

Device Platform: Mobile

Date tested: 2 years ago

Using the spread operator

17.2M/s

Using Object.assign

9.6M/s

View exact numbers

Test name	Executions per second
✓ Using the spread operator	17,228,930 Ops/sec
Using Object.assign	9,580,448 Ops/sec

Tests:

Using the spread operator
const firstObject = { sampleData: 'Hello world' } const secondObject = { moreData: 'foo bar' } const finalObject = { ...firstObject, ...secondObject };
Using Object.assign
const firstObject = { sampleData: 'Hello world' } const secondObject = { moreData: 'foo bar' } const finalObject = Object.assign({}, firstObject, secondObject);