Run results for: JavaScript spread operator vs Object.assign performance

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:60.0) Gecko/20100101 Firefox/60.0

Browser: Firefox 60

Operating system: Windows

Device Platform: Desktop

Date tested: 5 years ago

Test name	Executions per second
Using the spread operator	2426057.0 Ops/sec
Using Object.assign	3624066.0 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' } function newState(a, b) { return Object.assign({}, a, b); } const finalObject = newState(firstObject, secondObject);