for-vs-map

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

var testArray = [1,2,3,4,5,6,7,8,9,10,11,12,13];
var resultat = [2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26];

suite
    .add('forHoley', () => forHoley(testArray))
    .add('forPush', () => forPush(testArray))
    .add('map', () => mapTest(testArray))
    .on('cycle', event => console.log(String(event.target)))
    .on('complete', function() {console.log('Fastest is ' + this.filter('fastest').map('name'))})
    .run({ 'async': true });

function forHoley(array) {
    var length = array.length,
        result = Array(length);

    for(var i = 0; i < length; i++) {
        result[i] = array[i] * 2;
    }

    return result;
}

function forPush(array) {
    var result = [];

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

    return result;
}

function mapTest(arr) {
    return arr.map(function(item) {return item * 2})
}

expect(forHoley(testArray)).toEqual(resultat);
expect(forPush(testArray)).toEqual(resultat);
expect(mapTest(testArray)).toEqual(resultat);
    for(var i = 0; i < array.length; i++) {
        result[i] = array[i] * 2;
    }

    return result;
}

function mapTest(arr) {
    return arr.map(function(item) {return item * 2})
}

expect(forTest(testArray)).toEqual(resultat);
expect(forSlowTest(testArray)).toEqual(resultat);
expect(mapTest(testArray)).toEqual(resultat);