Benchmark: Lodash _.union vs native Set() v3

HTML Preparation code:

<script type="text/javascript" src="https://cdn.jsdelivr.net/npm/lodash@4.17.10/lodash.min.js"></script>

Script Preparation code:

var a = [1, 2, 3, 4, 5]
var b = [3, 4, 5, 6, 7]

Tests:

_.union
var c = _.union(a, b) const d = c.contains(a => a===3)
Set()
var c = new Set(a, b) const d = c.has(3)
Set() convert back to array
var c = new Set(a, b)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
_.union
Set()
Set() convert back to array

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

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

LLMs can make mistakes. Check important info.

**Benchmark Overview**

The provided benchmark is designed to compare the performance of Lodash's `_.union` function with native JavaScript's `Set()` data structure.

**Options Compared**

Two options are compared:

1. **Lodash _.union**: A custom implementation using Lodash's `_union` function.
2. **Native Set() v3**: The built-in `Set` object in JavaScript, which is implemented in C++ and optimized for performance.

**Pros and Cons of Each Approach**

### Lodash _.union

Pros:

* Easy to use: Simply call the `_union` function with two arrays as arguments.
* Familiar API: Uses a well-known library (Lodash), making it easier for developers to understand and maintain.

Cons:

* Performance overhead: Using a library like Lodash introduces a small performance overhead due to the need to load the library, create an instance of it, and call its functions.

### Native Set()

Pros:

* Optimized for performance: The `Set` object is implemented in C++ and optimized for performance, making it generally faster than any custom implementation.
* Memory efficiency: Sets use a compact, memory-efficient data structure that can handle large numbers of unique elements.

Cons:

* Unfamiliar API: The `Set` API is not as well-known as other JavaScript objects, requiring more effort to understand and use correctly.
* Limited flexibility: Sets are designed for storing unique values and do not provide the same level of control as custom array implementations.

**Library and Purpose**

The library used in this benchmark is Lodash, a popular JavaScript utility library that provides a wide range of functions for tasks like string manipulation, object transformation, and more. In this case, the `_union` function is used to combine two arrays into a single array with no duplicates.

**Special JS Feature or Syntax**

None mentioned in the provided code snippets.

**Benchmark Preparation Code**

The preparation code sets up two initial arrays `a` and `b`, which will be used as input for both benchmark tests. The Lodash library is loaded from a CDN using an HTML script tag.

**Individual Test Cases**

There are three test cases:

1. **_.union**: Tests the performance of Lodash's `_union` function.
2. **Set()**: Tests the performance of native JavaScript's `Set()` data structure.
3. **Set() convert back to array**: Tests the performance of converting a Set back into an array.

**Latest Benchmark Result**

The latest benchmark result shows the execution times per second for each test case, measured on a Chrome 111 browser on a Windows Desktop platform:

* **Set()**: 2588013.0 executions/second
* **Set() convert back to array**: 2577717.0 executions/second
* **_.union**: 0.0 executions/second (likely due to the high overhead of loading and executing Lodash code)

Note that the results may vary depending on the specific test environment and hardware configuration.

Related benchmarks:

Lodash _.union vs native Set() v3 (version: 0)

Comparing performance of: _.union vs Set() vs Set() convert back to array

Created: 3 years ago by: Guest

Jump to the latest result

_.union

Set()

Set() convert back to array

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):