Benchmark: DifferenceBy vs native

Script Preparation code:

var array1 = [{name: 'foo', value: 3},{name:'bar', value: 4},{name:'x', value: 0}]
var array2 = [{name: 'foo', type: 'a'},{name:'baz', type:'b'},{name:'x', type:'c'}]

Tests:

_.differenceBy
var difference = _.differenceBy(array1, array2, 'name')
Native
if (array1) { if (array2) { var difference = [array1.map(a => a.name), array2.map(a => a.name)] .reduce((a, b) => a.filter(c => !b.includes(c))) } else { array1 } }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
_.differenceBy
Native

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:135.0) Gecko/20100101 Firefox/135.0

Browser/OS: Firefox 135 on Windows

View result in a separate tab

Test name	Executions per second
_.differenceBy	2726302.2 Ops/sec
Native	7720903.5 Ops/sec

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

LLMs can make mistakes. Check important info.

I'll break down the provided benchmark and explain what's being tested, compared, and their pros and cons.

**Benchmark Overview**

The provided JSON represents a JavaScript microbenchmark that tests two approaches to find the difference between two arrays: `_.differenceBy` from the Lodash library and a native implementation.

**Test Cases**

There are two test cases:

1. **_.differenceBy**: This test case uses the Lodash library's `differenceBy` function, which takes three arguments:
	* The first array (`array1`)
	* The second array (`array2`)
	* A key function (`'name'`) that extracts the common property from both objects
The test case prepares two arrays, `array1` and `array2`, with different values for the `'name'` property.
2. **Native**: This test case implements the difference-by algorithm manually using JavaScript. It uses a map operation to create an array of names from both input arrays, and then filters out the common elements using another filter method.

**Library: Lodash**

Lodash is a popular JavaScript library that provides a collection of reusable functions for various tasks, such as utility functions, array operations, and more. The `differenceBy` function is part of this library and allows you to find the difference between two arrays based on a common property.

**Pros of Using Lodash (`_.differenceBy`)**

* Readability: The implementation is concise and easy to understand, thanks to the high-quality documentation provided by Lodash.
* Performance: Lodash's implementation is optimized for performance, using techniques like caching and memoization to avoid unnecessary computations.
* Maintainability: By using a well-maintained library, you can focus on other aspects of your project rather than rewriting common algorithms.

**Cons of Using Lodash (`_.differenceBy`)**

* Additional dependency: Your project needs to include the Lodash library, which might add overhead in terms of download size and loading time.
* Potential performance impact: Although Lodash's implementation is optimized, it still introduces an extra layer of indirection that might affect performance.

**Pros of Native Implementation**

* No additional dependencies: Your project doesn't need to include any external libraries or dependencies.
* Customization: You can modify the algorithm to suit your specific needs and requirements.

**Cons of Native Implementation**

* Increased complexity: The implementation is more complex, requiring a deeper understanding of JavaScript's array operations and filtering techniques.
* Potential performance impact: Without optimizations, the native implementation might be slower than Lodash's optimized version.

**Other Alternatives**

If you prefer not to use Lodash or want to explore other options, here are some alternatives:

1. `Array.prototype.filter()`: You can achieve a similar result using the `filter()` method on both input arrays, like this: `[array1.map(a => a.name), array2.map(a => a.name)].reduce((a, b) => a.filter(c => !b.includes(c)))`.
2. `Set` and `intersection()`: Another approach is to use two sets (one for each array) and compute their intersection using the `intersection()` method.
3. Libraries like `fast-async-mathlib`, which provides optimized implementations of various mathematical operations, including set theory functions.

In summary, both approaches have their pros and cons. If you need readability and performance, Lodash's `differenceBy` is a good choice. However, if you prefer to avoid dependencies or customize the algorithm, the native implementation might be a better fit.

Related benchmarks:

DifferenceBy vs native (version: 0)

Comparing performance of: _.differenceBy vs Native

Created: 5 years ago by: Guest

Jump to the latest result

_.differenceBy

Native

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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