Run results for: Lodash uniqBy vs loop+Map

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36 Edg/131.0.0.0

Browser: Chrome 131

Operating system: Windows

Device Platform: Desktop

Date tested: one year ago

Test name	Executions per second
_.unqiBy	3055.5 Ops/sec
Loop	4262.2 Ops/sec

HTML Preparation code:

<script src='https://cdn.jsdelivr.net/npm/lodash@4.17.10/lodash.min.js'></script>
<script>
const arr = (new Array(10000)).fill().map((e, i) => ({ key: i%2 === 1 ? i : i -1, val1: 'abcdf', val: 'abcdf' }));
</script>

Tests:

_.unqiBy
const res = _.uniqBy(arr, 'key')
Loop
const result = new Map(); for (const item of arr) { const key = item['key']; result.set(key, item); } const res = result.values();

Run results for: Lodash uniqBy vs loop+Map

_.unqiBy

Loop