Benchmark: unique elements in array using filter v2.3

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 = [8,9,34,12,4,2,1,5,7,2,8,1,25,7,1,2,3,1,2,4,2,3,5,3,9,34,12,4,2,1,5,7,2,8,1,25,7,1,2,3,1,2,4,2,39,34,12,4,2,1,5,7,2,8,1,25,7,1,2,3,1,2,4,2,39,34,12,4,2,1,5,7,2,8,1,25,7,1,2,3,1,2,4,2,39,34,12,4,2,1,5,7,2,8,1,25,7,1,2,3,1,2,4,2,39,34,12,4,2,1,5,7,2,8,1,25,7,1,2,3,1,2,4,2,39,34,12,4,2,1,5,7,2,8,1,25,7,1,2,3,1,2,4,2,3,7,2,8,1,25,7,1,2,3,1,2,4,2,37,2,8,1,25,7,1,2,3,1,2,4,2,37,2,8,1,25,7,1,2,3,1,2,4,2,37,2,8,1,25,7,1,2,3,1,2,4,2,3]

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:

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

LLMs can make mistakes. Check important info.

Measuring JavaScript performance is an essential task in software development, and MeasuringThat.net provides a useful platform for it.

The provided benchmark tests the uniqueness of elements in an array using three different approaches:

1. **_.uniq(elements)** (using Lodash library):
	* **Approach:** This approach uses the `uniq` function from the Lodash library, which is a utility function that returns a new array with unique values.
	* **Pros:** The Lodash library provides a simple and efficient way to perform this operation. It's also well-documented and widely used in the JavaScript community.
	* **Cons:** Since it uses an external library, there might be slight overhead due to the initialization of the library.
2. **[...new Set(elements)]**:
	* **Approach:** This approach creates a new `Set` object from the input array and then converts it back to an array using the spread operator (`[...]`). The `Set` data structure automatically removes duplicates, making this approach efficient.
	* **Pros:** This approach is fast and simple, with an average time complexity of O(n). It's also a native JavaScript solution, eliminating any external library dependencies.
	* **Cons:** Creating a new `Set` object can be memory-intensive for large arrays. Additionally, this approach may not work as expected if the input array contains non-unique elements that are considered equal (e.g., due to a custom equality check).
3. **elements.filter((v, i, a) => a.indexOf(v) === i)**:
	* **Approach:** This approach uses the `filter` method to create a new array with only unique elements. It achieves this by comparing each element's index in the original array (`a.indexOf(v)` ) to its value (`v`). If they're equal, it means the element is unique.
	* **Pros:** This approach is also efficient (O(n)) and uses native JavaScript functions, making it a good choice for performance-critical code paths.
	* **Cons:** It may be slightly slower than the `Set` approach due to the extra function calls involved.

All three approaches have their strengths and weaknesses. The Lodash library's `uniq` function is convenient but might introduce some overhead. The `Set` approach is fast and simple, but it requires memory for the temporary set data structure. The filter-based approach is another efficient option with native JavaScript functions, but it may require more complex logic.

**Additional considerations:**

*   When using external libraries like Lodash, ensure that they're up-to-date and compatible with your target browsers.
*   For very large arrays or performance-critical code paths, consider the memory requirements of each approach.
*   Be aware of potential edge cases for unique elements, such as custom equality checks.

**Other alternatives:**

*   If you want to implement a custom solution without relying on external libraries, you can use a simple hash table-based approach (e.g., by creating an object with keys equal to the input array values).
*   Another option is to use the `Array.prototype.reduce()` method along with a custom equality check function to remove duplicates.

Related benchmarks:

unique elements in array using filter v2.3 (version: 0)

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

Created: 4 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

No previous run results

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