Object-keys-vs-for-in

Object-keys-vs-for-in.js

var Benchmark = require('benchmark');
var suite = new Benchmark.Suite;

var testObject = {};

for (var s = 0; s < 1000; s++) {
    testObject[s] = Math.floor(Math.random() * 10000);
}

console.log('Testing iteration of object')
suite
    .add('Object key and forEach', () => objectKeysForEach(testObject))
    .add('Object key and for', () => objectKeysFor(testObject))
    .add('Object key and for in', () => objectKeysForIn(testObject))
    .add('Object key and for in 2', () => objectKeysForIn(testObject))
    .on('cycle', event => console.log(String(event.target)))
    .on('complete', function() {console.log('Fastest is ' + this.filter('fastest').map('name'))})
    .run({ 'async': true });


function objectKeysForEach(obj) {
    var result = {};
    Object.keys(obj).forEach(key => {
        result[key] = obj[key] * 2;
    });

    return result;
}

function objectKeysFor(obj) {
    var result = {};
    var keys = Object.keys(obj);

    for (var i = 0; i < keys.length; i++) {
        var key = keys[i];
        result[key] = obj[key] * 2;
    }

    return result;
}

function objectKeysForIn(object) {
    var result = {};

    for (var key in object) {
        if (object.hasOwnProperty(key)) {
            result[key] = object[key] * 2;
        }
    }

    return result;
}

function objectKeysForInS(object) {
    var result = {};

    for (var key in object) {
        result[key] = object[key] * 2;
    }

    return result;
}