Run results for: Object.entries VS Object.keys VS Object.keys with extra array VS Object.entries without array

Run details:

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 17_0_3 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/17.0.1 Mobile/15E148 Safari/604.1

Browser: Mobile Safari 17

Operating system: iOS 17.0.3

Device Platform: Mobile

Date tested: 2 years ago

Object.entries without array

97K/s

Object.entries

91K/s

Object.keys

65K/s

Object.keys with extra array

35K/s

View exact numbers

Test name	Executions per second
✓ Object.entries without array	96,762 Ops/sec
Object.entries	91,195 Ops/sec
Object.keys	65,276 Ops/sec
Object.keys with extra array	35,289 Ops/sec

Script Preparation code:

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;
}

window.parentObj = {};

for (let i = 0; i < 100; i++) {
	window.parentObj[makeid()] = makeid();
}

Tests:

Object.entries
const newObj = {}; Object.entries(window.parentObj).forEach(([k, v], i) => { if ((i % 2) === 0) { newObj[k] = v; } });
Object.keys
const newObj = {}; Object.keys(window.parentObj).forEach((k, i) => { if ((i % 2) === 0) { newObj[k] = window.parentObj[k]; } });
Object.keys with extra array
const newObj = {}; Object.keys(window.parentObj).forEach((k, i) => { const [extraK, v] = [k, window.parentObj[k]] if ((i % 2) === 0) { newObj[extraK] = v; } });
Object.entries without array
const newObj = {}; Object.entries(window.parentObj).forEach((keyAndVal, i) => { if ((i % 2) === 0) { newObj[keyAndVal[0]] = keyAndVal[1]; } });