Benchmark: lodash union vs native set spread

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:

lodash
var c = _.union(a,b)
native set spread 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
lodash
native set spread back to array

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 the provided benchmark and explain what is tested, compared, and analyzed.

**Benchmark Overview**

The benchmark measures the performance difference between using `_.union` from Lodash library versus creating an array from a set with the spread operator (`[...]`) in JavaScript. The test cases are designed to compare these two approaches on arrays of similar sizes.

**Options Compared**

Two options are compared:

1. **Lodash _.union**: This is a utility function from the Lodash library that returns a new array containing all elements from the input arrays, without duplicates.
2. **Native Set Spread Back to Array**: This approach creates a set from the input arrays using the spread operator (`[...]`), and then converts it back to an array.

**Pros and Cons**

Here's a brief analysis of each approach:

* **Lodash _.union**:
	+ Pros: More concise, readable code; potentially more maintainable due to the familiarity with Lodash.
	+ Cons: Might incur overhead from loading the Lodash library; may not be optimized for performance.
* **Native Set Spread Back to Array**:
	+ Pros: Native implementation, likely optimized for performance; does not require external libraries.
	+ Cons: May have a steeper learning curve due to the set spread operator syntax; might result in less readable code.

**Library and Purpose**

In this benchmark, Lodash is used as a utility library, providing the `_.union` function. The purpose of using Lodash here is to demonstrate how performance can vary when using different libraries versus native JavaScript implementations.

**Special JS Feature or Syntax**

The use of the set spread operator (`[...]`) is a relatively recent feature in JavaScript (introduced in ECMAScript 2015) that allows creating an array from an iterable (like a set). This syntax is concise and readable, but might not be familiar to all developers.

**Other Alternatives**

If you're interested in exploring other approaches or alternatives:

* Using native `Array.prototype.reduce()` instead of Lodash's `_union()`.
* Utilizing the `Set` data structure directly (without spreading it back into an array) for both input and output.
* Comparing performance with different JavaScript engines, like SpiderMonkey, V8, or Safari.

In summary, this benchmark compares two approaches to creating a union from arrays: using Lodash's `_union()` function versus the native set spread operator syntax. The pros and cons of each approach have been highlighted, as well as some potential alternatives for further exploration.

Latest run results:

Run details: (Test run date: one month ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/128.0.0.0 Safari/537.36

Browser/OS: Chrome 128 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
lodash	4550215.0 Ops/sec
native set spread back to array	7921608.5 Ops/sec

Related benchmarks:

lodash union vs native set spread (version: 0)

Comparing performance of: lodash vs native set spread back to array

Created: 2 months ago by: Guest

Jump to the latest result

lodash

native set spread back to array

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):