Run results for: forEach vs for len vs for of

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/18.1.1 Safari/605.1.15

Browser: Safari 18

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: one year ago

.forEach

406K/s

for..of

396K/s

for

375K/s

View exact numbers

Test name	Executions per second
✓ .forEach	406,264 Ops/sec
for..of	396,207 Ops/sec
for	375,363 Ops/sec

HTML Preparation code:

<!--your preparation HTML code goes here-->

Script Preparation code:

function generateTestArray() {
  const testData = [];
  for (let i = 0; i < 100; ++i) {
    testData.push({
      height: i,
      width: i * 2,
      result: 0
    });
  }
  return testData;
}

Tests:

.forEach
const array = generateTestArray(); array.forEach((item) => { item.result = item.height * item.width; });
for..of
const array = generateTestArray(); for(const item of array) { item.result = item.height * item.width; }
for
const array = generateTestArray(); for (let i = 0; i < array.length; ++i) { array[i].result = array[i].height * array[i].width; }