Map-vs-Set-vs-Native.js

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

var testArray = [];

for (var s = 0; s < 5000; s++) {
    testArray.push(Math.floor(s * 0.1));
}

console.log('Testing used ids')
suite
    .add('Map', () => benchMap(testArray))
    .add('Set', () => benchSet(testArray))
    .add('Native', () => benchNative(testArray))
    .add('NativeTrue', () => benchNativeTrue(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 benchMap(arr) {
    var result = [];
    var usedIds = new Map();

    for(var i = 0; i < arr.length; i++) {
        var item = arr[i];

        usedIds.set(item, item);
    }

    for(var i = 0; i < 5500; i++) {
    	if(!usedIds.has(i))
    		result.push(i);
    }

    return result;
}

function benchSet(arr) {
    var result = [];
    var usedIds = new Set();

    for(var i = 0; i < arr.length; i++) {
        var item = arr[i];

        usedIds.add(item);
    }

    for(var i = 0; i < 5500; i++) {
    	if(!usedIds.has(i))
    		result.push(i);
    }

    return result;
}


function benchNative(arr) {
    var result = [];
    var usedIds = Object.create(null);

    for(var i = 0; i < arr.length; i++) {
        var item = arr[i];

        usedIds[item] = item;
    }

    for(var i = 0; i < 5500; i++) {
    	if(usedIds[i] !== i)
    		result.push(i);
    }

    return result;
}

function benchNativeTrue(arr) {
    var result = [];
    var usedIds = Object.create(null);

    for(var i = 0; i < arr.length; i++) {
        var item = arr[i];

        usedIds[item] = true;
    }

    for(var i = 0; i < 5500; i++) {
    	if(!usedIds[i])
    		result.push(i);
    }

    return result;
}