Run results for: Performance of JavaScript .forEach vs for in 3

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/130.0.0.0 Safari/537.36

Browser: Chrome 130

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: one year ago

Object.entries() for of

8K/s

Object.entries()

8K/s

for in

6K/s

for in with variable

6K/s

View exact numbers

Script Preparation code:

function generateTestObject() {
  const result = {};
  for (let i = 0; i < 1000; ++i) {
    result['v'+i] = i
  }
  return result;
}

Tests:

Object.entries()
const object = generateTestObject(); Object.entries(object).forEach(([key, value]) => { const test = key + '' + value })
for in
const object = generateTestObject(); for(key in object){ const test = key + '' + object[key] }
for in with variable
const object = generateTestObject(); for(key in object){ const value = object[key] const test = key + '' + value }
Object.entries() for of
const object = generateTestObject(); for(const [key, value] of Object.entries(object)){ const test = key + '' + value }