map-vs-obj.js

'use strict';

const obj = {};
const map = new Map;
const total = 99999999;

for (var i = 0; i < 100000; i++) {
    obj['_'+i] = true;
    map.set('_'+i, true);
}

let init = new Date().getTime();
let count = 0
while (count < total) {
    map['_10'];
    map['ok'];
    map['_99999'];
    map['_2398413984'];
    count++;
}
console.log(new Date().getTime() - init);

init = new Date().getTime();
count = 0
while (count < total) {
    obj['_10'];
    obj['ok'];
    obj['_99999'];
    obj['_2398413984'];
    count++;
}
console.log(new Date().getTime() - init);

init = new Date().getTime();
count = 0
while (count < total) {
    map.get('_10') // true
    map.get('ok') // undefined
    map.get('_99999') // true
    map.get('_2398413984') // undefined
    count++;
}
console.log(new Date().getTime() - init);

init = new Date().getTime();
count = 0
while (count < total) {
    obj._10 // true
    obj.ok // false
    obj._99999 // true
    obj._2398413984 // false
    count++;
}
console.log(new Date().getTime() - init);