Benchmark: Lodash difference vs Set & Filter vs Map

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 < 100000; i++) {
  arr1.push({"index": i});
}

var arr2 = [];
for(let i = 49000; i >= 0; i--) {
  arr2.push(arr1[i*2]);
}

Tests:

Lodash
const notInArr = _.difference(arr2, arr1)
Set & Filter
const arr2Set = new Set(arr2); const notInArr2 = arr1.filter(value => !arr2Set.has(value));
map
const arr2Map = new Map(arr2.map((e2) => ([e2.index, e2]))); const notInArr2 = arr1.filter(value => !arr2Map.has(value));

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Lodash
Set & Filter
map

Fastest: N/A

Slowest: N/A

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

LLMs can make mistakes. Check important info.

**Benchmark Explanation**

The provided JSON represents a JavaScript benchmark that compares the performance of three different approaches to find elements not present in an array:

1. **Lodash**: Uses the `_difference` function from the Lodash library, which takes two arrays as input and returns a new array containing only the elements present in the first array but not in the second.
2. **Set & Filter**: Creates a `Set` object from the second array (`arr2`) and then uses the `filter` method to find elements in the first array (`arr1`) that are not present in the set.
3. **Map**: Creates a `Map` object from the second array (`arr2`) by mapping each element to its index, and then uses the `has` method to check if an element is present in the map.

**Options Compared**

The benchmark compares the performance of these three approaches:

* Lodash: `_difference`
* Set & Filter: using a `Set` object with `filter`
* Map: using a `Map` object with `has`

**Pros and Cons of Each Approach**

1. **Lodash**: Pros:
	* Convenient and concise syntax
	* Well-tested and optimized by the Lodash team
	* Supports various iteration modes (e.g., `_differenceBy`)
Cons:
	* Requires an additional library download (~2MB)
	* May incur overhead due to lazy evaluation
	* Limited control over implementation details
2. **Set & Filter**: Pros:
	* Lightweight and easy to understand
	* No additional libraries needed
	* Fast lookups using `Set` operations
Cons:
	* Requires two separate operations (creating the set and filtering)
	* May incur overhead due to array resizing for the set
3. **Map**: Pros:
	* Fast lookups using `has` method
	* Can be used with existing data structures (e.g., objects, arrays)
	* Low overhead compared to Set & Filter
Cons:
	* More complex syntax and implementation details
	* May require additional memory for the map

**Library and Purpose**

The Lodash library provides a wide range of functional programming utilities, including `_difference`, which is used in this benchmark. The `Set` object is a built-in JavaScript data structure that allows fast membership testing.

**Special JS Feature or Syntax**

There are no special features or syntaxes mentioned in the provided code. However, note that Lodash uses lazy evaluation, which can impact performance in some cases.

**Alternatives**

Other alternatives to these approaches include:

1. **Using `find` and `includes`**: Instead of creating a set or map, you could use `find` and `includes` methods to find the first element not present in the array.
2. **Implementing custom iteration**: You could write your own iterative solution using loops instead of relying on built-in functions like Set & Filter.
3. **Using other libraries or frameworks**: Depending on the specific requirements, you might consider using other libraries or frameworks that provide optimized implementations for set and map operations.

Overall, the choice of approach depends on the trade-offs between performance, readability, and maintainability.

Latest run results:

Run details: (Test run date: 2 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:106.0) Gecko/20100101 Firefox/106.0

Browser/OS: Firefox 106 on Windows

View result in a separate tab

Test name	Executions per second
Lodash	35.9 Ops/sec
Set & Filter	86.2 Ops/sec
map	59.3 Ops/sec

Related benchmarks:

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

Comparing performance of: Lodash vs Set & Filter vs map

Created: 2 years ago by: Guest

Jump to the latest result

Lodash

Set & Filter

map

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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