`new Map()` быстрее объектов и массивов

function TEST(/*this: DedicatedWorkerGlobalScope*/) 
{ 
	console.log = (...mess) => this.postMessage(mess) 
	console.log('START\n') 
 
	var indexes = []; 
	{ 
		let n = 2000000; 
		while (n > 0) 
		{ 
			indexes.push(Math.random() * 2000000); 
			n--; 
		} 
	} 
 
	let looper = (callback) => 
	{ 
		let n = 2000000; 
		while (n > 0) 
		{ 
			callback(indexes[n], n); 
			n--; 
		} 
	} 
 
	let timer = (mess, callback) => 
	{ 
		let start = Date.now(); 
		callback() 
		console.log(mess, Date.now() - start); 
	} 
 
	{//#region test int 
		let map = new Map(); 
		let obj = {}; 
		let ray = []; 
 
		timer('Map int key set took: ', () => looper((key, index) => map.set(key, index))); 
		timer('Obj int key set took: ', () => looper((key, index) => obj[key] = index)); 
		timer('ray int key set took: ', () => looper((key, index) => ray[key] = index)); 
		console.log(' '); 
		timer('Map int key get took: ', () => looper((key, index) => { let dummylet = map.get(key); dummylet; })); 
		timer('Obj int key get took: ', () => looper((key, index) => { let dummylet = obj[key]; dummylet; })); 
		timer('ray int key get took: ', () => looper((key, index) => { let dummylet = ray[key]; dummylet; })); 
	}//#endregion 
 
	console.log('\n\n'); 
 
	{//#region test string 
		let map = new Map(); 
		let obj = {}; 
		let ray = []; 
 
		timer('Map string key set took: ', () => looper((key, index) => map.set('' + key, '' + index))); 
		timer('Obj string key set took: ', () => looper((key, index) => obj['' + key] = '' + index)); 
		timer('ray string key set took: ', () => looper((key, index) => ray['' + key] = '' + index)); 
		console.log(' '); 
		timer('Map string key get took: ', () => looper((key, index) => { let dummylet = map.get('' + key); dummylet; })); 
		timer('Obj string key get took: ', () => looper((key, index) => { let dummylet = obj['' + key]; dummylet; })); 
		timer('ray string key get took: ', () => looper((key, index) => { let dummylet = ray['' + key]; dummylet; })); 
	}//#endregion 
 
	console.log('\nEND') 
} 
 
 
const genCode = (f/*: Function*/) => `;(${f})();this.close()` 
 
let code = genCode(TEST) 
 
let blob = new Blob([code], { type: 'text/javascript' }) 
let url = URL.createObjectURL(blob) 
 
let myWorker = new Worker(url) 
myWorker.onmessage = ({ data }) => console.log.apply(console, data) 
myWorker.onerror = console.error