Run results for: Perf _.groupBy vs native Array.reduce

Run details:

User agent: Mozilla/5.0 (X11; Linux x86_64; rv:88.0) Gecko/20100101 Firefox/88.0

Browser: Firefox 88

Operating system: Linux

Device Platform: Desktop

Date tested: 3 years ago

Test name	Executions per second
_.groupBy	2576220.2 Ops/sec
Native Array reduce	3163406.2 Ops/sec

HTML Preparation code:

<script type="text/javascript" src="https://cdn.jsdelivr.net/npm/underscore@1.13.1/underscore-umd-min.js"></script>

Tests:

_.groupBy
const a = ["one", "two", "three"]; _.groupBy(a, "length");
Native Array reduce
const a = ["one", "two", "three"]; a.reduce((acc, curr) => { acc[curr.length] = (acc[curr.length] || []); acc[curr.length].push(curr); return acc; }, {});