Run results for: uniqBy performance lodash vs native

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/151.0.0.0 Safari/537.36

Browser: Chrome 151

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: one month ago

Benchmark engine: Benchmark.js

javascript

17.3M/s

native

9.5M/s

lodash

9.4M/s

View exact numbers

HTML Preparation code:

<script>https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.15/lodash.core.js</script>

Script Preparation code:

var data = [{a: 1}, {a: 2}, {a: 3}, {a: 4}, {a: 5}, {a: 6}, {a: 7}, {a: 8}, {a: 1}];

Tests:

lodash
_.uniqBy(data, 'a');
javascript
const sortBy = (key) => { return (a, b) => (a[key] > b[key]) ? 1 : (b[key] > a[key] ? -1 : 0); }; const uniqBy = (arr, a) => { arr.sort(sortBy(a)); const arr1 = []; arr1.push(arr[0]); for (let index = 1; index < arr.length; index++) { if (arr[index-1] && arr[index -1].a !== arr[index].a) { arr1.push(arr[index]); } } return arr1; } uniqBy(data, 'a')
native
function uniqueBy(arr, prop){ const record = [] const seen = {} for (let i = 0, len = arr.length; i < len; ++i) { // Notice the len = arr.length const item = arr[i] const val = item[prop] if (!seen[val]) { seen[val] = 1 record.push(item) } } } uniqueBy(data, 'a')