Run results for: Object spread vs new Map vs Object assign with complex data

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36

Browser: Chrome 120

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 2 years ago

new Map

90K/s

Object spread

17K/s

Object assign

17K/s

View exact numbers

Test name	Executions per second
✓ new Map	89,877 Ops/sec
Object spread	17,376 Ops/sec
Object assign	17,049 Ops/sec

Script Preparation code:

var data = new Array(1000000).fill(undefined).map((_,i) => i)
var obj = data.reduce((obj, idx) => {obj['idx' + Date.now()] = {name: 'Name: ' + Date.now(), age: idx}; return obj}, {});
var map = new Map(Object.entries(obj));

Tests:

Object spread
var copy = {...obj}
new Map
var copy = new Map(map)
Object assign
var copy = Object.assign({}, obj)