Benchmark: Lodash uniqBy vs Set with Array of object

HTML Preparation code:

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

Script Preparation code:

var myArr = Array.from({
    length: 16000
}, () => ({ value: Math.floor(Math.random() * 1000) }));

var myCopy = null;

Tests:

Lodash uniqBy
myCopy = _.uniqBy(myArr, 'value').map(({ value }) => value);
new Set() Destructuring
myCopy = [...new Set(myArr.map(({ value }) => value))]
uniq for loop
var seen = {}; var out = []; const len = myArr.length; var j = 0; for (var i = 0; i < len; i += 1) { var item = myArr[i].value; if (seen[item] !== 1) { seen[item] = 1; out[j++] = item; } } myCopy = out;
uniq by forEach
var result = []; myArr.forEach((item) => { if (result.indexOf(item.value) < 0) { result.push(item.value); } }); myCopy = result;
uniq by filter
var mapMyArr = myArr.map(({ value }) => value); myCopy = mapMyArr.filter((value, index, array) => array.indexOf(value) === index);

Historical Performance Data aggregated from 65 community runs

Desktop Results:

Chrome 56 runs

uniq for loop

6K/s

Lodash uniqBy

4K/s

new Set() Destructuring

2K/s

uniq by forEach

862/s

uniq by filter

506/s

Fastest: uniq for loop (11.4x faster)

View exact numbers

✓ uniq for loop: 5,750 ops/sec
• Lodash uniqBy: 4,068 ops/sec
• new Set() Destructuring: 2,467 ops/sec
• uniq by forEach: 862 ops/sec
• uniq by filter: 506 ops/sec

Firefox 9 runs

uniq for loop

9K/s

Lodash uniqBy

4K/s

new Set() Destructuring

3K/s

uniq by forEach

185/s

uniq by filter

98/s

Fastest: uniq for loop (93.3x faster)

View exact numbers

✓ uniq for loop: 9,166 ops/sec
• Lodash uniqBy: 3,911 ops/sec
• new Set() Destructuring: 2,873 ops/sec
• uniq by forEach: 185 ops/sec
• uniq by filter: 98 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
Lodash uniqBy
new Set() Destructuring
uniq for loop
uniq by forEach
uniq by filter

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 5 months ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/145.0.0.0 Safari/537.36

Browser/OS: Chrome 145 on Mac OS X 10.15.7

View result in a separate tab

uniq for loop

14K/s

Lodash uniqBy

5K/s

new Set() Destructuring

2K/s

uniq by forEach

934/s

uniq by filter

515/s

View exact numbers

Test name	Executions per second
✓ uniq for loop	13,934 Ops/sec
Lodash uniqBy	4,644 Ops/sec
new Set() Destructuring	2,045 Ops/sec
uniq by forEach	934 Ops/sec
uniq by filter	515 Ops/sec

Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks.

**Benchmark Description**

The benchmark tests four different approaches to remove duplicates from an array of objects while preserving the original order:

1. **Lodash `uniqBy`**: Uses Lodash's `uniqBy` function, which removes duplicate elements from an array based on a unique function.
2. **`new Set()` with Array destructuring**: Uses a `Set` data structure to remove duplicates and then uses array destructuring to create a new array.
3. **For loop**: Iterates through the array using a traditional for loop and checks each element against a set of seen values to avoid duplicates.
4. **`forEach()` with `indexOf()`**: Iterates through the array using `forEach()` and checks if an element is already present in the array using `indexOf()`.

**Options Compared**

The four options are compared in terms of their performance, efficiency, and readability.

* **Lodash `uniqBy`**: Pros: concise, readable, and easy to use. Cons: may not be as efficient as other approaches.
* **`new Set()` with Array destructuring**: Pros: efficient, straightforward, and easy to understand. Cons: requires a slight learning curve for those unfamiliar with sets.
* **For loop**: Pros: well-known, familiar algorithm. Cons: verbose, error-prone, and less readable than the other options.
* **`forEach()` with `indexOf()`**: Pros: concise, readable. Cons: may not be as efficient as other approaches.

**Libraries and Special JS Features**

The benchmark uses Lodash's `uniqBy` function, which is a utility library that provides a simple way to remove duplicates from an array based on a unique function.

There are no special JavaScript features or syntax used in this benchmark.

**Benchmark Preparation Code**

The preparation code generates an array of 16,000 objects with random values and copies the array to ensure correct results. The `myCopy` variable is initialized to null, which will be populated with the result of each benchmarking approach.

**HTML Preparation Code**

The HTML code includes a link to Lodash's CDN, which loads the necessary library for the `uniqBy` function.

**Other Alternatives**

There are other approaches to removing duplicates from an array in JavaScript, such as:

* Using `Array.prototype.filter()` and checking if each element is already present in the array.
* Using `Array.prototype.every()` and checking if each element meets a certain condition.
* Using a recursive approach with a helper function.

These alternatives may have their own trade-offs in terms of performance, efficiency, and readability.

Lodash uniqBy vs Set with Array of object (version: 4)

Lodash uniqBy vs [...new Set()]

Comparing performance of: `Lodash uniqBy vs new Set() Destructuring vs uniq for loop vs uniq by forEach vs uniq by filter`

Created: 5 years ago by: Registered User

Go to the latest result

Lodash uniqBy

new Set() Destructuring

uniq for loop

uniq by forEach

uniq by filter

Historical Performance Data aggregated from 65 community runs

Desktop Results:

Chrome 56 runs

Firefox 9 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):

Lodash uniqBy vs Set with Array of object (version: 4)

Lodash uniqBy vs [...new Set()]

Comparing performance of: Lodash uniqBy vs new Set() Destructuring vs uniq for loop vs uniq by forEach vs uniq by filter

Created: 5 years ago by: Registered User

Go to the latest result

Lodash uniqBy

new Set() Destructuring

uniq for loop

uniq by forEach

uniq by filter

Historical Performance Data aggregated from 65 community runs

Desktop Results:

Chrome 56 runs

Firefox 9 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):

Related benchmarks

Comparing performance of: `Lodash uniqBy vs new Set() Destructuring vs uniq for loop vs uniq by forEach vs uniq by filter`