Run results for: Object.key vs Object.value vs Object.entries

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:82.0) Gecko/20100101 Firefox/82.0

Browser: Firefox 82

Operating system: Windows

Device Platform: Desktop

Date tested: 4 years ago

Test name	Executions per second
entries	61798.1 Ops/sec
keys	46348.5 Ops/sec
values	33684.1 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.parentObj = {};

for (let i = 0; i < 100; i++) {
    window.parentObj[makeid()] = {
        innerVal: makeid()
    };
}

​x
 
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.parentObj = {};​for (let i = 0; i < 100; i++) {    window.parentObj[makeid()] = {        innerVal: makeid()    };}

Tests:

entries

const newObj = {};
Object.entries(window.parentObj).forEach(([k, v], i) => {
  if ((i % 2) === 0) {
	newObj[k] = v;    
  }
});

 
const newObj = {};Object.entries(window.parentObj).forEach(([k, v], i) => {  if ((i % 2) === 0) {    newObj[k] = v;      }});

keys

const newObj = {};
Object.keys(window.parentObj).forEach((k, i) => {
  if ((i % 2) === 0) {
	newObj[k] = window.parentObj[k];    
  }
});

 
const newObj = {};Object.keys(window.parentObj).forEach((k, i) => {  if ((i % 2) === 0) {    newObj[k] = window.parentObj[k];      }});

values

const newObj = {};
Object.values(window.parentObj).forEach((k, i) => {
  if ((i % 2) === 0) {
	newObj[k] = window.parentObj[k];    
  }
});

 
const newObj = {};Object.values(window.parentObj).forEach((k, i) => {  if ((i % 2) === 0) {    newObj[k] = window.parentObj[k];      }});