Run results for: Object.entries vs for of

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/115.0.0.0 Safari/537.36

Browser: Chrome 115

Operating system: Windows

Device Platform: Desktop

Date tested: one year ago

Test name	Executions per second
entries	245184.8 Ops/sec
for	29392.5 Ops/sec
foreach	467750.2 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.parentArr = [];

for (let i = 0; i < 100; i++) {
	window.parentArr.push(makeid());
}

Tests:

entries
const newObj = {}; for (const [i, v] of window.parentArr.entries()) { if ((i % 2) === 0) { newObj[i] = v; } }
for
const newObj = {}; for (let i = 0; i < window.parentArr.length; i++) { if ((i % 2) === 0) { newObj[i] = window.parentArr[i]; } }
foreach
const newObj = {}; window.parentArr.forEach((v, i) => { if ((i % 2) === 0) { newObj[i] = v; } })

Run results for: Object.entries vs for of

entries

for

foreach