Benchmark: lodash flatmap vs array.flat

HTML Preparation code:

<script src="https://cdn.jsdelivr.net/lodash/4.16.0/lodash.min.js"></script>

Script Preparation code:

var x = [1,2,3]
var y = [4,5,6]
var z = [x,y]

Tests:

lodash.flatMap
_.flatMap(z)
array.flat
z.flat()

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
lodash.flatMap
array.flat

Fastest: N/A

Slowest: N/A

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

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I'll explain the benchmark and its components.

**Benchmark Overview**

MeasureThat.net is a website that allows users to create and run JavaScript microbenchmarks. The provided benchmark compares two approaches: `_.flatMap` from Lodash (a utility library) and `array.flat()`, which is a built-in method in modern JavaScript arrays.

**Options Compared**

The benchmark tests two options:

1. **Lodash's `_flatMap()`**: This function flattens an array by recursively calling itself on each sub-array.
2. **`array.flat()`**: This method returns a new array with all sub-arrays flattened into it.

**Pros and Cons of Each Approach**

* **`.flatMap()` (Lodash)**:
	+ Pros: Generally faster than `flat()` because it avoids creating intermediate arrays.
	+ Cons: Requires an external library, which can add to the benchmark's overhead. Also, its performance can be affected by the size of the input array and the recursion depth.
* **`array.flat()`**:
	+ Pros: Built-in method, no external dependencies, efficient for large arrays.
	+ Cons: Can create intermediate arrays, which might lead to higher memory usage.

**Library Used**

The benchmark uses Lodash (version 4.16.0), a popular utility library that provides various functions for manipulating data structures, working with strings and numbers, and more. The `_flatMap()` function is part of this library.

**Special JS Feature/Syntax**

Neither of the approaches mentioned above uses any special JavaScript features or syntax. They are both standard array methods that are widely supported by most modern browsers.

**Other Alternatives**

If you need to flatten an array in JavaScript without using `flat()` or `_flatMap()`, you could use a simple recursive function, like this:
```javascript
function flatten(arr) {
  if (!Array.isArray(arr)) return [arr];
  let result = [];
  for (let i of arr) {
    result.push(...flatten(i));
  }
  return result;
}
```
This approach would likely be slower than the built-in `flat()` method or Lodash's `_flatMap()`, but it demonstrates an alternative way to achieve the same result.

Keep in mind that the best approach depends on your specific use case and performance requirements. MeasureThat.net helps you compare different approaches and find the most efficient solution for your needs.

Related benchmarks:

lodash flatmap vs array.flat (version: 0)

Comparing performance of: lodash.flatMap vs array.flat

Created: 5 years ago by: Guest

Jump to the latest result

lodash.flatMap

array.flat

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

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