Benchmark: lodash difference vs ES6 Set (large data set)

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 < 50000; i++) {
  arr1.push('' + i);
}

var arr2 = [];
for(let i = 4990; i >= 0; i--) {
  arr2.push('' + i);
}

Tests:

_difference
const finalArray = _.difference(arr2, arr1)
Set/Filter
const outList = new Set([...arr1]); const finalArray = arr2.filter(value => !outList.has(value));

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
_difference
Set/Filter

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

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

LLMs can make mistakes. Check important info.

The provided JSON represents two JavaScript microbenchmarks for testing the performance of two different approaches to find the difference between two large arrays.

**Benchmark 1: Lodash `_difference`**

The benchmark measures the performance of Lodash's `_difference` function, which takes two arrays as input and returns a new array containing only the elements that are present in the first array but not in the second. The two arrays, `arr1` and `arr2`, are populated with 50,000 and 49,990 integers, respectively.

**Benchmark 2: ES6 Set + Filter**

The benchmark measures the performance of a combination of an ES6 Set and the `filter` method to find the difference between the same two arrays. The process works as follows:

1. Create an ES6 Set from the first array (`arr1`) using the spread operator (`[...arr1]`). This allows for efficient lookups.
2. Filter the second array (`arr2`) by checking if each element is not present in the set created from `arr1` using the `has` method.

**Options compared**

The two approaches being tested are:

* Lodash's `_difference` function
* ES6 Set + Filter combination

**Pros and Cons**

**Lodash `_difference`**

Pros:

* Optimized for performance by Lodash's team
* Easy to use, as it provides a simple method signature
* Works with any type of elements, not just numbers or strings

Cons:

* Requires including an additional library (Lodash)
* May have performance overhead due to the need to create a new array

**ES6 Set + Filter**

Pros:

* Uses native JavaScript features, which are generally faster than third-party libraries
* Does not require including any additional libraries
* Can be more flexible, as it allows for custom comparison functions

Cons:

* Requires manual creation of a set and handling edge cases (e.g., duplicate elements)
* May have performance overhead due to the need to create an intermediate array or set

**Library**

Lodash is a popular JavaScript utility library that provides many functional programming helpers, including `_difference`. It can be included in a project by adding a script tag referencing its CDN or downloading and importing it locally.

**Special JS feature/Syntax**

There is no special JavaScript feature or syntax used in these benchmarks. Both approaches use standard JavaScript features like arrays, sets, loops, and filter methods.

**Other alternatives**

If you want to test alternative approaches for finding the difference between two large arrays, some other options could include:

* Using `Array.prototype.filter()` with a custom comparison function
* Implementing a manual algorithm using indexing or iteration
* Utilizing WebAssembly (WASM) performance optimizations

Related benchmarks:

lodash difference vs ES6 Set (large data set) (version: 0)

Comparing performance of: _difference vs Set/Filter

Created: 3 years ago by: Guest

Jump to the latest result

_difference

Set/Filter

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):