Benchmark: unique elements in array using filter - lodash 4.17.21

HTML Preparation code:

<script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.21/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)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
_.uniq
set
uniq by filter

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 2 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/121.0.0.0 Safari/537.36

Browser/OS: Chrome 121 on Windows

View result in a separate tab

Test name	Executions per second
_.uniq	7902636.0 Ops/sec
set	4935947.0 Ops/sec
uniq by filter	11516957.0 Ops/sec

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

LLMs can make mistakes. Check important info.

I'll break down the explanation into smaller parts to make it easier to understand.

**Benchmark Definition JSON**

The provided JSON represents a benchmark test case for measuring the performance of JavaScript code that removes duplicate elements from an array. The test has three variants:

1. Using Lodash's `uniq` function (version 4.17.21).
2. Creating a new Set and spreading its elements into an array.
3. Filtering the original array using a callback function.

The script preparation code defines an array `elements` with duplicate values, and the HTML preparation code includes the necessary Lodash library file (`lodash.js`) version 4.17.21.

**Options Compared**

Each option has its pros and cons:

1. **Lodash's `uniq` function**: This is a popular utility function that removes duplicates from an array while preserving order. The pros include:
	* Efficient implementation (O(n) complexity).
	* Simple usage.
	* Well-documented.
The cons include:
	* External dependency on Lodash library.
	* May not be suitable for all use cases (e.g., when preserving the original array's index).

2. **Creating a new Set and spreading its elements**: This approach is simple, efficient, and doesn't require any external libraries.
	* Pros:
		+ Lightweight (no external dependency).
		+ Fast (O(n) complexity).
		+ Easy to understand and implement.
	The cons include:
		+ May not preserve the original array's index.
		+ Requires manual handling of null or undefined values.

3. **Filtering the original array**: This approach uses a callback function to filter out duplicates while preserving the original array's order.
	* Pros:
		+ Preserves the original array's index.
		+ Simple implementation.
	The cons include:
		+ May have performance issues (O(n^2) complexity in the worst case).
		+ More complex implementation compared to the Set-based approach.

**Library: Lodash**

Lodash is a popular JavaScript utility library that provides a wide range of functions for tasks like array manipulation, string manipulation, and more. The `uniq` function is one of its most useful utilities for removing duplicates from arrays while preserving order.

**Special JS Feature/ Syntax (None)**

There are no special JavaScript features or syntaxes used in this benchmark test case.

**Other Alternatives**

If you need to measure the performance of other approaches, here are some alternatives:

* Using `Array.prototype.filter()` and `Array.prototype.indexOf()`
* Implementing a custom implementation using loops or recursive functions
* Using other libraries like ` underscore` or `ramda`

Keep in mind that each approach has its own strengths and weaknesses, and the choice of which one to use depends on your specific requirements and preferences.

Related benchmarks:

unique elements in array using filter - lodash 4.17.21 (version: 0)

Comparing performance of: _.uniq vs set vs uniq by filter

Created: 5 years ago by: Guest

Jump to the latest result

_.uniq

set

uniq by filter

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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