Benchmark: _.union vs native Set() implementation

HTML Preparation code:

<script src='https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.5/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)
Set()
var c = [...new Set(a, b)]

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
_.union
Set()

Fastest: N/A

Slowest: N/A

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

LLMs can make mistakes. Check important info.

Let's break down what's being tested in this benchmark and compare the two approaches.

**What is being tested?**

The benchmark measures the performance difference between Lodash's `_.union()` method and a native JavaScript implementation using the `Set` object.

**Options compared:**

1. **Lodash's `_.union()` method**: This is a utility function provided by the Lodash library, which takes two arrays as input and returns a new array containing all unique elements from both arrays.
2. **Native JavaScript implementation using `Set` object**: This approach uses the built-in `Set` object to achieve the same result as Lodash's `_.union()` method.

**Pros and Cons of each approach:**

1. **Lodash's `_.union()` method:**
	* Pros:
		+ Easy to use and understand, especially for developers familiar with Lodash.
		+ Provides a convenient way to perform set operations without requiring manual implementation.
	* Cons:
		+ Adds an additional dependency on the Lodash library.
		+ May introduce overhead due to function call and object creation costs.
2. **Native JavaScript implementation using `Set` object:**
	* Pros:
		+ No dependencies or overhead from a third-party library.
		+ Can be optimized for performance since it's implemented in native code.
	* Cons:
		+ Requires manual implementation, which can be more error-prone and harder to understand.
		+ May not be as convenient to use as Lodash's `_.union()` method.

**Library:**

The library being tested is Lodash.js, a popular JavaScript utility library that provides various functions for tasks such as string manipulation, array manipulation, and more. In this case, the `_.union()` function is being used to compare its performance with a native implementation.

**Special JS feature or syntax:**

There are no special features or syntaxes introduced in this benchmark beyond standard JavaScript.

**Benchmark preparation code explanation:**

The script preparation code creates two arrays, `a` and `b`, which will be used as input for the `_.union()` method. The array values are chosen to test a set of duplicate elements (e.g., `[1, 2, 3, 4, 5]` and `[3, 4, 5, 6, 7]`). This setup allows the benchmark to focus on the performance difference between Lodash's `_.union()` method and the native implementation.

**Other alternatives:**

Besides using Lodash's `_.union()` method and a native JavaScript implementation using the `Set` object, other alternatives might include:

1. Using the `Array.prototype.reduce()` method with an accumulator to combine the elements of two arrays.
2. Utilizing a custom implementation that leverages the `Map` data structure instead of the `Set` object.

These alternative approaches would require additional testing and optimization to determine their performance characteristics compared to Lodash's `_.union()` method and the native JavaScript implementation.

Latest run results:

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

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36

Browser/OS: Chrome 74 on Windows

View result in a separate tab

Test name	Executions per second
_.union	1308777.4 Ops/sec
Set()	1190374.4 Ops/sec

Related benchmarks:

_.union vs native Set() implementation (version: 0)

Comparing performance of: _.union vs Set()

Created: 5 years ago by: Guest

Jump to the latest result

_.union

Set()

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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