Benchmark: returns unique values in array

HTML Preparation code:

<script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.11/lodash.js"></script>

Script Preparation code:

var elements = [1,2,3,1,2,4,2,3,5,3]

Tests:

_.uniq
_.uniq(elements)
set
[...new Set(elements)]
uniq by filter
elements.filter((v, i, a) => a.indexOf(v) === i)
Array.from with set
Array.from(new Set(elements))

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
_.uniq
set
uniq by filter
Array.from with set

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 9 months ago)

User agent: Mozilla/5.0 (X11; Linux x86_64; rv:144.0) Gecko/20100101 Firefox/144.0

Browser/OS: Firefox 144 on Linux

View result in a separate tab

_.uniq

11.8M/s

uniq by filter

5.7M/s

Array.from with set

4.8M/s

set

4.6M/s

View exact numbers

Test name	Executions per second
✓ _.uniq	11,754,201 Ops/sec
uniq by filter	5,715,912 Ops/sec
Array.from with set	4,824,437 Ops/sec
set	4,649,288 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and explain what's being tested, compared, and what are the pros and cons of each approach.

**Benchmark Overview**

The benchmark measures the performance of three different approaches to find unique values in an array:

1. Using the `_.uniq` function from Lodash
2. Creating a new Set from the array using the spread operator (`[...new Set(elements)]`)
3. Filtering the original array using the `indexOf` method and comparing the index with the value

**Library: Lodash**

Lodash is a popular JavaScript utility library that provides a wide range of functions for tasks such as data manipulation, string manipulation, and functional programming.

In this benchmark, the `_.uniq` function is used to find unique values in an array. The `_` symbol is often referred to as "underscore" and is used to denote a namespace or prefix for Lodash functions.

**JavaScript Features/Syntax**

The test cases use the following JavaScript features/syntax:

* Spread operator (`[...new Set(elements)]`)
* Arrow function syntax (`(v, i, a) => a.indexOf(v) === i`)

**Approaches Compared**

The three approaches compared are:

1. **_.uniq**: This uses the `_.uniq` function from Lodash to find unique values in an array. The implementation is likely to be optimized for performance and might use a hash table or other data structure to achieve this.
2. **Set**: This creates a new Set from the array using the spread operator (`[...new Set(elements)]`). Sets are designed to automatically eliminate duplicates, making this approach efficient but potentially slower than others due to the overhead of creating a new set and converting elements to strings (for hashing).
3. **uniq by filter**: This uses the `indexOf` method to find unique values in an array. The implementation iterates over the original array, keeping track of seen values using the `indexOf` method, which has a time complexity of O(n^2). This approach is likely to be slower than others due to its quadratic time complexity.

**Pros and Cons**

Here's a brief summary of each approach:

* **_.uniq**: Pros: optimized for performance, uses hash table or similar data structure; Cons: relies on Lodash library.
* **Set**: Pros: efficient in eliminating duplicates, but creates a new set and converts elements to strings; Cons: potentially slower due to overhead.
* **uniq by filter**: Pros: simple and easy to understand; Cons: slow due to quadratic time complexity.

**Other Alternatives**

Some other approaches that could be used to find unique values in an array include:

* Using `Array.prototype.reduce()` or a similar function to accumulate unique values
* Using a custom implementation using arrays, maps, or sets
* Using a library like `fastest-unique` which provides optimized implementations for finding unique elements

Keep in mind that the best approach will depend on the specific use case and performance requirements.

returns unique values in array (version: 0) Benchmark.js

Comparing performance of: `_.uniq vs set vs uniq by filter vs Array.from with set`

Created: 3 years ago by: Guest

Go to the latest result

_.uniq

set

uniq by filter

Array.from with set

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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

returns unique values in array (version: 0) Benchmark.js

Comparing performance of: _.uniq vs set vs uniq by filter vs Array.from with set

Created: 3 years ago by: Guest

Go to the latest result

_.uniq

set

uniq by filter

Array.from with set

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: `_.uniq vs set vs uniq by filter vs Array.from with set`