Run results for: JavaScript spread operator vs object update performance

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36

Browser: Chrome 131

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: one year ago

Using update

189.9M/s

Using Object.assign

41.2M/s

View exact numbers

Test name	Executions per second
✓ Using update	189,864,352 Ops/sec
Using Object.assign	41,249,580 Ops/sec

Tests:

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