Benchmark: Lodash difference vs Set & Filter (large)

HTML Preparation code:

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

Script Preparation code:

var arr1 = [];
for(let i = 0; i < 10000; i++) {
  arr1.push('' + i);
}

var arr2 = [];
for(let i = 490; i >= 0; i--) {
  arr2.push('' + i);
}

Tests:

Lodash
const notInArr1 = _.difference(arr2, arr1) const notInArr2 = _.difference(arr1, arr2)
Set & Filter
const arr1Set = new Set(); const arr2Set = new Set(); arr1.forEach(value => arr1Set.add(value)); arr2.forEach(value => arr2Set.add(value)); const notInArr1 = arr2.filter(value => !arr1Set.has(value)); const notInArr2 = arr1.filter(value => !arr2Set.has(value));
Set & Filter (new set)
const arr1Set = new Set([...arr1]); const arr2Set = new Set([...arr2]); const notInArr1 = arr2.filter(value => !arr1Set.has(value)); const notInArr2 = arr1.filter(value => !arr2Set.has(value));

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Lodash
Set & Filter
Set & Filter (new set)

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/537.36 (KHTML, like Gecko) Chrome/108.0.0.0 Safari/537.36

Browser/OS: Chrome 108 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Lodash	2721.9 Ops/sec
Set & Filter	235.2 Ops/sec
Set & Filter (new set)	157.9 Ops/sec

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

LLMs can make mistakes. Check important info.

I'll break down the benchmark and its test cases to explain what's being tested, compared, and their pros and cons.

**Benchmark Overview**

The benchmark is designed to compare three approaches for finding elements in two large arrays:

1. Using Lodash (`_difference` method)
2. Using a `Set` and filtering (`filter` method)
3. Using a `Set` and filtering with new sets (creating new sets from the original arrays)

**Test Cases**

Each test case measures the execution time of one of these approaches.

### 1. Lodash

The benchmark uses Lodash's `_difference` method to find elements in `arr2` that are not in `arr1`. This method returns a new array containing only the unique elements from the first array and rejecting duplicates.

**Pros:**

* Efficient for finding differences between two arrays, especially when one of them is large.
* Leveraging Lodash's optimized implementation and caching to improve performance.

**Cons:**

* Adds extra memory usage due to creating a new array.
* May incur additional overhead if `arr1` or `arr2` are very large.

### 2. Set & Filter

This approach uses two separate `Set` objects to store unique elements from both arrays and then filters out the common elements using the `filter` method.

**Pros:**

* Does not create new arrays, reducing memory usage.
* Can be more efficient for finding intersections between sets.

**Cons:**

* May incur additional overhead due to set creation and filtering.
* Could potentially lead to slower performance if the filter operation is expensive.

### 3. Set & Filter (new set)

This approach creates new `Set` objects from both arrays using array spread (`[...arr]`) and then filters out common elements.

**Pros:**

* Similar to the previous approach, but with a potential performance improvement due to optimized array creation.
* Does not create additional memory for filtering results.

**Cons:**

* Requires creating two new sets, which can lead to increased memory usage.
* Still incurs overhead from set creation and filtering.

**Library and Syntax Considerations**

* Lodash is a popular utility library that provides a wide range of functions for tasks like array manipulation, math operations, and more. In this benchmark, it's used for the `_difference` method.
* `Set` objects are a built-in JavaScript data structure that allows you to store unique values.

**Device-Specific Considerations**

The test results were obtained on a Chrome 108 browser running on a Mac with macOS 10.15.7. The device platform and operating system may affect the benchmark's performance, as some features or optimizations might be unavailable or less efficient on certain platforms.

**Other Alternatives**

If you need to compare other approaches for finding elements in two arrays, consider using:

* `Array.prototype.some()` and `Array.prototype.find()`: These methods can be used to find common or unique elements between two arrays.
* `Promise.all()`: This method can be used to compare the performance of multiple array operations in parallel.

When choosing an approach, consider factors like memory usage, filter complexity, and potential overhead from set creation.

Related benchmarks:

Lodash difference vs Set & Filter (large) (version: 0)

Comparing performance of: Lodash vs Set & Filter vs Set & Filter (new set)

Created: one year ago by: Guest

Jump to the latest result

Lodash

Set & Filter

Set & Filter (new set)

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):