Run results for: lodash groupBy vs Array.reduce 500k

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/130.0.0.0 Safari/537.36 Edg/130.0.0.0

Browser: Chrome 130

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 6 months ago

Test name	Executions per second
Lodash	68.3 Ops/sec
Native	40.3 Ops/sec

HTML Preparation code:

<script src='https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.5/lodash.min.js'></script>

​x
 
​
<script src='https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.5/lodash.min.js'></script>

Script Preparation code:

var max2 = 500000;

var data = [];
for (var i = 0; i <= max2; i++) { data.push({ id: i }); }

 
var max2 = 500000;​var data = [];for (var i = 0; i <= max2; i++) { data.push({ id: i }); }

Tests:

Lodash
_.groupBy(data, ({ id }) => id)
_.groupBy(data, ({ id }) => id)

Native

// Using reduce to mimic _.groupBy
const grouped = data.reduce((acc, item) => {
    // Initialize an array for this id if it doesn't exist
    if (!acc[item.id]) acc[item.id] = [];
    // Push the item into the array for this id
    acc[item.id].push(item);
    return acc;
}, {});

 
// Using reduce to mimic _.groupByconst grouped = data.reduce((acc, item) => {    // Initialize an array for this id if it doesn't exist    if (!acc[item.id]) acc[item.id] = [];    // Push the item into the array for this id    acc[item.id].push(item);    return acc;}, {});​

Run results for: lodash groupBy vs Array.reduce 500k

Lodash

Native