Benchmark: Lodash _.union vs native Set() vs Concat & filter

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]
Array.prototype.cfunion = function (array) {
  var conc = this.concat(array);
  return conc.filter((i,p)=>{
    return conc.indexOf(i) == p
  });
};

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)
Concat & Filter
var c = a.cfunion(b)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

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

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/18.0.1 Safari/605.1.15

Browser/OS: Safari 18 on Mac OS X 10.15.7

View result in a separate tab

Concat & Filter

8.8M/s

Set()

7.1M/s

_.union

5.0M/s

Set() convert back to array

4.6M/s

View exact numbers

Test name	Executions per second
✓ Concat & Filter	8,762,077 Ops/sec
Set()	7,146,668 Ops/sec
_.union	4,968,239 Ops/sec
Set() convert back to array	4,612,684 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into the benchmark and explain what's being tested.

**Benchmark Overview**

The test compares three approaches to create a union of two arrays:

1. `Lodash _.union`
2. `native Set()` (using the built-in `Set` constructor)
3. `Concat & Filter`

These three approaches are compared because they represent different ways to solve the same problem: merging two arrays into one without duplicates.

**Options Compared**

* `_.union`: Uses Lodash's utility function to merge two arrays.
* `native Set()`: Utilizes JavaScript's built-in `Set` constructor, which is a collection of unique values.
* `Concat & Filter`: Merges two arrays using the `concat()` method and then filters out duplicates using an arrow function.

**Pros and Cons**

1. **_.union (Lodash)**:
	* Pros: Concise and readable code, Lodash's utility functions are well-maintained and widely used.
	* Cons: Requires an additional library dependency (Lodash).
2. **native Set()**:
	* Pros: Fast and efficient, as `Set` is implemented in native JavaScript.
	* Cons: May require some manual effort to convert the resulting set back into an array.
3. **Concat & Filter**:
	* Pros: No additional library dependencies required, can be easily optimized for performance.
	* Cons: More verbose code compared to Lodash's `_.union` and may not be as readable.

**Library and Syntax**

The benchmark uses the Lodash library, which is a popular utility library for JavaScript. It provides a range of functions for tasks like array manipulation, object creation, and more.

**Special JS Features or Syntax**

There are no special JS features or syntax used in this benchmark that would require prior knowledge of specific language features. However, the use of `Set` as a data structure is a common pattern in JavaScript, so familiarity with basic Set operations may be helpful.

**Other Alternatives**

If you're interested in exploring alternative approaches, here are some additional options:

* Using `Array.from()` to convert a `Set` back into an array: This approach is similar to the `Concat & Filter` method but uses `Array.from()` instead.
* Using a custom implementation of the union operation using bitwise operations or other algorithms.
* Using a different library or framework that provides optimized implementations for array merging and filtering.

These alternatives might offer better performance or readability, depending on your specific use case and requirements.

Lodash _.union vs native Set() vs Concat & filter (version: 0) Benchmark.js

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

Created: 7 years ago by: Guest

Go to the latest result

_.union

Set()

Set() convert back to array

Concat & Filter

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() vs Concat & filter (version: 0) Benchmark.js

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

Created: 7 years ago by: Guest

Go to the latest result

_.union

Set()

Set() convert back to array

Concat & Filter

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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

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