Benchmark: lodash flatten vs array.flat

HTML Preparation code:


<script src='https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.5/lodash.min.js'></script>

Tests:

spread
const arrayA = ['hi', 'hi', 'hi', 'hi']; const arrayB = ['hi', 'hi', 'hi', 'hi']; const flattened = [ arrayA, arrayB ].flat(); console.log(flattened);
lodash flatten
const arrayA = ['hi', 'hi', 'hi', 'hi']; const arrayB = ['hi', 'hi', 'hi', 'hi']; const flattened = []; const sourceObject = [ arrayA, arrayB ]; sourceObject.forEach((array) => { flattened.push(array) }); _.flatten(flattened); console.log(flattened);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
spread
lodash flatten

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 3 days ago)

User agent: Mozilla/5.0 (X11; Linux x86_64; rv:131.0) Gecko/20100101 Firefox/131.0

Browser/OS: Firefox 131 on Linux

View result in a separate tab

Test name	Executions per second
spread	238143.6 Ops/sec
lodash flatten	238133.7 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the JavaScript microbenchmark and explain what is being tested.

**Benchmark Definition**

The benchmark compares two approaches to flattening arrays: using `Array.flat()` (also known as the spread operator) and using Lodash's `_flatten()` function.

**Options Compared**

1. **Spread Operator (`Array.flat()`)**: This method uses the spread operator (`...`) to expand the array into a new array.
2. **Lodash's `_flatten()` function**: This is a utility function from the popular Lodash library that flattens an array of arrays into a single array.

**Pros and Cons**

* **Spread Operator (`Array.flat()`)**:
	+ Pros: Simple, concise, and widely supported by modern browsers.
	+ Cons: May not be as efficient as other methods, especially for large arrays.
* **Lodash's `_flatten()` function**:
	+ Pros: More flexible and customizable than the spread operator.
	+ Cons: Requires including an additional library (Lodash) and may have slower performance due to the overhead of function calls.

**Library: Lodash**

Lodash is a popular JavaScript utility library that provides a wide range of functions for tasks such as array manipulation, string manipulation, and more. The `_flatten()` function is one of its many utilities designed to simplify common programming tasks.

**Special JS Feature/Syntax: None**

Neither of the two approaches used in this benchmark relies on any special JavaScript features or syntax.

**Other Alternatives**

If you want to flatten an array without using `Array.flat()` or Lodash's `_flatten()`, you can use other methods such as:

1. Using `concat()` and `push()`: Iterate over each element of the original array, pushing it onto a new array.
2. Using a for loop and push(): Similar to the previous approach, but with a more concise syntax.
3. Using `reduce()`: Use the `reduce()` method to accumulate elements from an array into a single array.

Keep in mind that these alternatives may have different performance characteristics than using `Array.flat()` or Lodash's `_flatten()` function.

I hope this explanation helps you understand what is being tested in the MeasureThat.net benchmark!

Related benchmarks:

lodash flatten vs array.flat (version: 0)

lodash flatten vs spread

Comparing performance of: spread vs lodash flatten

Created: 4 years ago by: Guest

Jump to the latest result

spread

lodash flatten

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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