MeasureThat.net

Run results for: Object from entries - Object.assign vs. spread vs. simple mutate

Tests the difference in performance when reconstructing an object from its entries via reduce, between using Object.assign and the object rest spread operator

Go to the benchmark
Run details:
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/111.0.0.0 Safari/537.36
Chrome 111
Mac OS X 10.15.7
Desktop
2 years ago
Test name Executions per second
Object.assign 1064047.6 Ops/sec
Spread 1667742.9 Ops/sec
Simple mutate 6850338.5 Ops/sec
Script Preparation code:
AخA
 
window.entries = [
  ['one', 1],
  ['two', 2],
  ['three', 3],
  ['four', 4],
  ['five', 5]
];
Tests:

  • Object.assign

     
    window.entries.reduce((obj, [key, value]) => Object.assign(obj, {[key]: value}), {})

  • Spread

     
    window.entries.reduce((obj, [key, value]) => ({...obj, [key]: value}), {})

  • Simple mutate

     
    window.entries.reduce((obj, [key, value]) => {
      obj[key] = value;
      return obj;
    }, {})