Run results for: Object.values vs for in loop

Run details:

User agent: Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/73.0.3683.103 YaBrowser/19.4.3.370 Yowser/2.5 Safari/537.36

Browser: Yandex Browser 19

Operating system: Windows 8.1

Device Platform: Desktop

Date tested: 4 years ago

Test name	Executions per second
mapForIn	27671.7 Ops/sec
mapValues	26379.9 Ops/sec

Script Preparation code:

const obj = {};

for (let i = 0; i >= 100; i++) { 
  obj[i] = { id: i };
};

console.log(obj);

const mapForIn = (func) => {
  const arr = [];
  
  for (let key in obj) {
    if (Object.hasOwnProperty(obj)) {
      arr.push(func(obj[key], arr.length - 1));
    }
  }
             
  return arr;
}

const mapValues = (func) => Object.values(obj).map(func);

Tests:

mapForIn
const obj = {}; for (let i = 0; i >= 100; i++) { obj[i] = { id: i }; }; console.log(obj); const mapForIn = (func) => { const arr = []; for (let key in obj) { if (Object.hasOwnProperty(obj)) { arr.push(func(obj[key], arr.length - 1)); } } return arr; } mapForIn((item, index) => item);
mapValues
const obj = {}; for (let i = 0; i >= 100; i++) { obj[i] = { id: i }; }; console.log(obj); const mapValues = (func) => Object.values(obj).map(func); mapValues((item, index) => item);