Benchmark: Lodash "unionBy" test

HTML Preparation code:

<script src='https://cdn.jsdelivr.net/npm/lodash@4.17.10/lodash.min.js'></script>

Script Preparation code:

var users = [
  { 'name': 'barney',  'age': 36 },
];

var newUsers = [
  { 'name': 'fred',    'age': 40 },
  { 'name': 'barney',  'age': 36 },
  { 'name': 'pebbles', 'age': 2 }
];

for(let i = 0; i < 2000; i++) {
  var newUser = { 'name': 'user_' + i, 'age': Math.floor(Math.random() * i) };
  newUsers.push(newUser);
  users.push(newUser)
}

Tests:

unionBy
const unionUsers2 = _.unionBy(newUsers, users, 'name'); console.log('ub', unionUsers2.length)
test
let obj = {} users.forEach((user) => obj[user.name] = user) newUsers.forEach((user) => obj[user.name] = user) console.log('test', Object.values(obj).length)

Historical Performance Data aggregated from 10 community runs

Desktop Results:

Chrome 10 runs

unionBy

3K/s

test

2K/s

Fastest: unionBy (1.9x faster)

View exact numbers

✓ unionBy: 3,383 ops/sec
• test: 1,820 ops/sec

Results show median performance across all community submissions. Run this benchmark yourself to verify on your device.

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
unionBy
test

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/18.5 Safari/605.1.15

Browser/OS: Safari 18 on Mac OS X 10.15.7

View result in a separate tab

unionBy

7K/s

test

6K/s

View exact numbers

Test name	Executions per second
✓ unionBy	7,171 Ops/sec
test	6,221 Ops/sec

Lodash "unionBy" test (version: 0)

Comparing performance of: `unionBy vs test`

Created: 5 years ago by: Guest

Go to the latest result

unionBy

test

Historical Performance Data aggregated from 10 community runs

Desktop Results:

Chrome 10 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

Lodash "unionBy" test (version: 0)

Comparing performance of: unionBy vs test

Created: 5 years ago by: Guest

Go to the latest result

unionBy

test

Historical Performance Data aggregated from 10 community runs

Desktop Results:

Chrome 10 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

Related benchmarks

Comparing performance of: `unionBy vs test`