Run results for: Map vs Object reduce - MeasureThat.net

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/88.0.4324.50 Safari/537.36

Browser: Chrome 88

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 4 years ago

Test name	Executions per second
Map	19840.0 Ops/sec
Object assignment	52153.9 Ops/sec
Object spread	3575.4 Ops/sec
Object.assign	329.8 Ops/sec

Script Preparation code:

var arr = Array.from({
    length: 1000
}, (_, i) => i);

Tests:

Map
arr.reduce((map, i) => map.set(i, i), new Map());
Object assignment
arr.reduce((obj, i) => { obj[i] = i; return obj; }, {});
Object spread
arr.reduce((obj, i) => ({ ...obj, [i]: i }), {});
Object.assign
arr.reduce((obj, i) => Object.assign(obj, { [i]: i }), {});