Benchmark: Lodash _.union vs native Set()

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)
Set()
var c = new Set(a, b)
Set() convert back to array
var c = new Set(a, b) var d = Array.from(c)

Historical Performance Data aggregated from 50 community runs

Desktop Results:

Chrome 41 runs

Set()

6.0M/s

Set() convert back to array

4.2M/s

_.union

3.9M/s

Fastest: Set() (1.5x faster)

View exact numbers

✓ Set(): 5,982,972 ops/sec
• Set() convert back to array: 4,209,372 ops/sec
• _.union: 3,921,848 ops/sec

Firefox 9 runs

_.union

4.2M/s

Set()

2.9M/s

Set() convert back to array

2.1M/s

Fastest: _.union (2.0x faster)

View exact numbers

✓ _.union: 4,158,813 ops/sec
• Set(): 2,940,596 ops/sec
• Set() convert back to array: 2,051,553 ops/sec

Results show median performance across all community submissions. Run this benchmark yourself to verify on your device.

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:

Run details: (Test run date: 11 months ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/26.0.1 Safari/605.1.15

Browser/OS: Safari 26 on Mac OS X 10.15.7

View result in a separate tab

Set()

13.0M/s

Set() convert back to array

8.6M/s

_.union

8.5M/s

View exact numbers

Test name	Executions per second
✓ Set()	12,974,650 Ops/sec
Set() convert back to array	8,639,212 Ops/sec
_.union	8,511,797 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark.

**What is being tested?**

The benchmark compares the performance of two approaches to perform set operations:

1. `Lodash _.union`: This uses the `_.union()` function from the Lodash library, which merges two arrays into a new array with unique elements.
2. `Native Set()`: This uses the built-in `Set` data structure in JavaScript to merge two arrays.

**Options compared:**

* `Lodash _.union`
* `Set()`
* `Set() convert back to array`

**Pros and Cons of each approach:**

1. **Lodash _.union**
	* Pros:
		+ Easy to use with existing Lodash library.
		+ Can handle more complex data structures, such as objects or arrays with duplicate values.
	* Cons:
		+ Adds extra overhead due to the library's complexity and indirection.
		+ May not be optimized for performance, especially on large datasets.
2. **Native Set()**
	* Pros:
		+ Fast and efficient, using native JavaScript functions.
		+ No additional overhead or dependencies required.
	* Cons:
		+ Requires manual conversion between arrays and sets (e.g., `Array.from(c)`).
		+ May not be suitable for handling complex data structures.

**Library and its purpose:**

The Lodash library is a collection of utility functions, including the `_.union()` function used in this benchmark. Its primary purpose is to provide a set of reusable functions for common programming tasks.

**Special JS feature or syntax:**

None mentioned in this benchmark, but it's worth noting that JavaScript has other features and syntax that may impact performance, such as:

* Array methods like `filter()`, `map()`, or `reduce()` might be used instead of `_.union()`.
* The use of `for...of` loops or other iteration constructs might be preferred over the Lodash library.

**Alternatives:**

If you want to compare other set operations, you could consider using:

1. `Array.prototype.reduce()`: Merging two arrays into a new array with unique elements.
2. `Array.prototype.concat()`: Combining two arrays into a single array (not ideal for finding duplicates).
3. Other libraries or modules that provide similar functionality to Lodash.

Keep in mind that the specific alternatives and their performance will depend on your use case and requirements.

Lodash _.union vs native Set() (version: 1) Benchmark.js

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

Created: 8 years ago by: Registered User

Go to the latest result

_.union

Set()

Set() convert back to array

Historical Performance Data aggregated from 50 community runs

Desktop Results:

Chrome 41 runs

Firefox 9 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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

Lodash _.union vs native Set() (version: 1) Benchmark.js

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

Created: 8 years ago by: Registered User

Go to the latest result

_.union

Set()

Set() convert back to array

Historical Performance Data aggregated from 50 community runs

Desktop Results:

Chrome 41 runs

Firefox 9 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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

Related benchmarks

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