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

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

The original does not correctly create the Set object from two arrays. Added alternate tests for using the Array functions, just in case they differ from spreading.

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

Created: one year ago by: Guest

Jump to the latest result

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.concat(b))
Set() using array spread
var c = new Set([...a, ...b])
Set() convert back to array
var c = new Set(a.concat(b)) var d = Array.from(c)
Set() convert back to array using array spread
var c = new Set([...a, ...b]) var d = [...c]

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

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

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; rv:109.0) Gecko/20100101 Firefox/118.0

Browser/OS: Firefox 118 on Mac OS X 10.15

View result in a separate tab

Test name	Executions per second
_.union	1784350.0 Ops/sec
Set()	1177155.5 Ops/sec
Set() using array spread	1028556.5 Ops/sec
Set() convert back to array	749202.8 Ops/sec
Set() convert back to array using array spread	779714.1 Ops/sec

Autogenerated LLM Summary (model gemma2:9b, generated 2 months ago):

LLMs can make mistakes. Check important info.

This benchmark compares different ways to find the union of two arrays in JavaScript.  It tests:

**Options:**

1. **`_.union(a, b)`**: Uses the `_.union()` function from the Lodash library. This function is designed to efficiently find the unique elements from multiple arrays.

2. **`new Set(a.concat(b))`**: Creates a new `Set` object by concatenating the two arrays and passing them into the `Set` constructor. Sets are data structures that inherently store only unique values.

3. **`new Set([...a, ...b])`**: Similar to the previous option but uses the array spread syntax (`...`) to combine the arrays before creating the `Set`.

4. **`new Set(a.concat(b))\r\nvar d = Array.from(c)`**: Creates a `Set`, then converts it back into an array using `Array.from()`. This tests the round-trip conversion from `Set` to array.

5. **`new Set([...a, ...b])\r\nvar d = [...c]`**: Similar to the previous option but uses the array spread syntax for the conversion back to an array.

**Pros and Cons:**

* **Lodash (`_.union`)**:  
    * **Pro**: Well-tested, optimized for performance. 
    * **Con**: Requires including the Lodash library in your project, adding some extra size.

* **`Set()`**:  
    * **Pro**:  Built-in to JavaScript, no external libraries needed. Sets are efficient for storing unique values.
    * **Con**: Can be less readable than using dedicated array methods if you're not familiar with Sets.

**Other Considerations:**

* **Library Choice**: If you frequently need advanced array operations, Lodash can be very helpful. However, if your project is small or you only need basic functionality, sticking to built-in JavaScript methods might be preferable.
* **Readability**:  Consider which approach is most readable and maintainable for your team.

**Alternatives:**

There are other ways to find the union of arrays in JavaScript:

* **Using `reduce`**: You can use the `reduce()` method to iterate through the arrays and keep track of unique values.
* **Manually iterating**:  You could manually loop through both arrays, adding elements to a new array only if they're not already present.

Let me know if you have any other questions!

Related benchmarks:

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

The original does not correctly create the Set object from two arrays. Added alternate tests for using the Array functions, just in case they differ from spreading.

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

Created: one year ago by: Guest

Jump to the latest result

_.union

Set()

Set() using array spread

Set() convert back to array

Set() convert back to array using array spread

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model gemma2:9b, generated 2 months ago):