Run results for: JavaScript spread operator vs Object.assign performance fixed 22222

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/128.0.0.0 Safari/537.36 Edg/128.0.0.0

Browser: Chrome 128

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: one year ago

Using the spread operator

8.7M/s

Using Object.assign

6.7M/s

View exact numbers

Test name	Executions per second
✓ Using the spread operator	8,724,351 Ops/sec
Using Object.assign	6,749,498 Ops/sec

Script Preparation code:

var firstObject = {
    "id": "2d10ffad-678b-4f9b-9d7e-1fd57879928d",
    "name": "Gon Freecss",
    "age": 100,
    "wallet": {
      "CNY": {
        "balance": 94306.78,
        "exchangeRate": 4.45
      },
      "USD": {
        "balance": 106.84,
        "exchangeRate": 29.96
      },
      "NTD": {
        "balance": 89171098.51,
        "exchangeRate": 1
      }
    }
  }
var secondObject = {
    "id": "b8eb86c2-1386-4b91-a87f-a3b16f6ebca5",
    "name": "Killua Zoldyck",
    "age": 96,
    "wallet2": {
      "CNY2": {
        "balance2": 59390.08,
        "exchangeRate2": 4.45
      },
      "USD2": {
        "balance2": 446.76,
        "exchangeRate2": 29.96
      },
      "NTD2": {
        "balance2": 49592399.77,
        "exchangeRate2": 1
      }
    }
  }

Tests:

Using the spread operator
const finalObject = { ...firstObject, ...secondObject };
Using Object.assign
const finalObject = Object.assign(firstObject, secondObject);