Run results for: Map vs Array.

Run details:

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/114.0.0.0 Safari/537.36

Browser: Chrome 114

Operating system: Linux

Device Platform: Desktop

Date tested: one year ago

Test name	Executions per second
Map	2469826.5 Ops/sec
Array	1668987.9 Ops/sec

Script Preparation code:

let map = new Map();
let arr = [];
let obj = {};

const randomU32 = function() {
	return Math.random() * (1 << 31) >>> 0;
}

​x
 
let map = new Map();let arr = [];let obj = {};​const randomU32 = function() {    return Math.random() * (1 << 31) >>> 0;}

Tests:

const randomU32 = function() {
	return Math.random() * (1 << 31) >>> 0;
}
const map = new Map();
map.set(randomU32(), true);

 
const randomU32 = function() {    return Math.random() * (1 << 31) >>> 0;}const map = new Map();map.set(randomU32(), true);

const randomU32 = function() {
	return Math.random() * (1 << 31) >>> 0;
}
const arr = [];
arr[randomU32()] = true;

 
const randomU32 = function() {    return Math.random() * (1 << 31) >>> 0;}const arr = [];arr[randomU32()] = true;