Run results for: Access Object, Map, Array, Set with n items

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:87.0) Gecko/20100101 Firefox/87.0

Browser: Firefox 87

Operating system: Windows

Device Platform: Desktop

Date tested: 3 years ago

Test name	Executions per second
Get from Object	5049476.0 Ops/sec
Get from Map	24874910.0 Ops/sec
Has key in Map	19982760.0 Ops/sec
Has key in Array OLD	9995.3 Ops/sec
Has key in Array NEW	9886.9 Ops/sec
Has key in Set	25101820.0 Ops/sec

Script Preparation code:

var length = 10000;
var key = '5000';
var obj = Array.from({length}).reduce((obj,_,index) => obj[index.toString()] = index, {});
var map = new Map(Array.from({length}).map((_,index) => [index.toString(), index]));

var arr = Array.from({length}).map((_,index) => index.toString());
var set = new Set(Array.from({length}).map((_,index) => index.toString()));

Tests:

Get from Object
var value = obj[key];
Get from Map
var value = map.get(key);
Has key in Map
var has = map.has(key);
Has key in Array OLD
var has = arr.indexOf(key) > -1;
Has key in Array NEW
var has = arr.includes(key);
Has key in Set
var has = set.has(key);

Run results for: Access Object, Map, Array, Set with n items

Get from Object

Get from Map

Has key in Map

Has key in Array OLD

Has key in Array NEW

Has key in Set