Benchmark: Spread vs Object.assign (mutation)

Script Preparation code:

window.object1 = {};
window.object2 = {};
window.object3 = {};
window.object4 = {};
window.object5 = {};
window.object6 = {};

function makeid() {
  var text = "";
  var possible = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";

  for (var i = 0; i < 5; i++)
    text += possible.charAt(Math.floor(Math.random() * possible.length));

  return text;
};

function populate(object) {
  for (let i = 0; i < 100; i++) {
    object[makeid()] = makeid();
  }
};

populate(object1);
populate(object2);
populate(object3);
populate(object4);
populate(object5);
populate(object6);

Tests:

Object.assign two objects
const object7 = Object.assign(object1, object2);
Spread two objects
const object7 = {...object1, ...object2};
Object.assign three objects
const object7 = Object.assign(object1, object2, object3);
Spread three objects
const object7 = {...object1, ...object2, ...object3};
Object.assign four objects
const object7 = Object.assign(object1, object2, object3, object4);
Spread four objects
const object7 = {...object1, ...object2, ...object3, ...object4};
Object.assign five objects
const object7 = Object.assign(object1, object2, object3, object4, object5);
Spread five objects
const object7 = {...object1, ...object2, ...object3, ...object4, ...object5};
Object.assign six objects
const object7 = Object.assign(object1, object2, object3, object4, object5, object6);
Spread six objects
const object7 = {...object1, ...object2, ...object3, ...object4, ...object5, ...object6};

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Object.assign two objects
Spread two objects
Object.assign three objects
Spread three objects
Object.assign four objects
Spread four objects
Object.assign five objects
Spread five objects
Object.assign six objects
Spread six objects

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/134.0.0.0 Safari/537.36 Edg/134.0.0.0

Browser/OS: Chrome 134 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Object.assign two objects	184918.9 Ops/sec
Spread two objects	41400.0 Ops/sec
Object.assign three objects	88899.8 Ops/sec
Spread three objects	21847.7 Ops/sec
Object.assign four objects	56413.3 Ops/sec
Spread four objects	14498.5 Ops/sec
Object.assign five objects	39123.2 Ops/sec
Spread five objects	10828.7 Ops/sec
Object.assign six objects	34141.0 Ops/sec
Spread six objects	8738.2 Ops/sec

Related benchmarks:

Spread vs Object.assign (mutation) (version: 1)

Comparing performance of: Object.assign two objects vs Spread two objects vs Object.assign three objects vs Spread three objects vs Object.assign four objects vs Spread four objects vs Object.assign five objects vs Spread five objects vs Object.assign six objects vs Spread six objects

Created: one year ago by: Guest

Jump to the latest result

Object.assign two objects

Spread two objects

Object.assign three objects

Spread three objects

Object.assign four objects

Spread four objects

Object.assign five objects

Spread five objects

Object.assign six objects

Spread six objects

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A