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

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:138.0) Gecko/20100101 Firefox/138.0

Browser: Firefox 138

Operating system: Windows

Device Platform: Desktop

Date tested: one year ago

Object assign

2.2M/s

new Map

438K/s

Object spread

437K/s

View exact numbers

Test name	Executions per second
✓ Object assign	2,212,219 Ops/sec
new Map	437,836 Ops/sec
Object spread	436,622 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)