Run results for: Object.values vs for in loop

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:123.0) Gecko/20100101 Firefox/123.0

Browser: Firefox 123

Operating system: Windows

Device Platform: Desktop

Date tested: 2 years ago

Benchmark engine: Benchmark.js

mapValues

193K/s

mapForIn

192K/s

View exact numbers

Test name	Executions per second
✓ mapValues	192,564 Ops/sec
mapForIn	192,287 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);