Benchmark: Array filter vs Lodash intersection 2

Script Preparation code:

var arr1 = [];
for (let i = 0; i < 1000; i++) {
  arr1.push(i);
}
arr1 = _.shuffle(arr1);

var arr2 = [];
for (let i = 500; i < 1500; i++) {
  arr2.push(i);
}
arr2 = _.shuffle(arr2);

Tests:

WARM UP
arr1.filter(item => arr2.indexOf(item) > -1);
Lodash
_.intersection(arr1, arr2);
Array find
arr1.filter(item => arr2.indexOf(item) > -1);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
WARM UP
Lodash
Array find

Fastest: N/A

Slowest: N/A

Latest run results:

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

LLMs can make mistakes. Check important info.

Let's dive into the explanation of the provided benchmark.

**Benchmark Overview**

The benchmark is comparing three approaches:

1. `Array.filter` with an anonymous function that checks if an item exists in another array (`arr2`) using `indexOf`.
2. `Lodash.intersection` which takes two arrays as input and returns a new array containing elements common to both.
3. `Array.find` which finds the first element that satisfies a condition (in this case, existence in `arr2`).

**Options Compared**

The benchmark is comparing:

* `Array.filter`: A built-in JavaScript method that creates a new array with all elements that pass the test implemented by the provided function.
* `Lodash.intersection`: A library function that takes two arrays as input and returns a new array containing elements common to both.

**Pros and Cons of Each Approach**

1. **`Array.filter`**:
	* Pros: Built-in, efficient, easy to understand and implement.
	* Cons: May not be the most readable or maintainable solution for complex logic.
2. **`Lodash.intersection`**:
	* Pros: Well-maintained, widely used library with extensive documentation, and often used in production code.
	* Cons: Adds an external dependency (Lodash), which may not be desirable for all projects.

**Library: Lodash**

Lodash is a popular JavaScript utility library that provides various functions for tasks like array manipulation, string processing, and more. The `intersection` function takes two arrays as input and returns a new array containing elements common to both. This allows developers to easily work with arrays without having to implement the logic themselves.

**Special JS Feature/Syntax: None**

There are no special JavaScript features or syntax used in this benchmark.

**Other Alternatives**

If you don't want to use Lodash, you can also implement an `intersection` function using vanilla JavaScript:

```javascript
function intersection(arr1, arr2) {
  return arr1.filter(item => arr2.includes(item));
}
```

This implementation uses the `includes` method, which is available in modern browsers and Node.js. For older environments, you may need to use a polyfill or implement your own `includes` function.

Keep in mind that this alternative approach may be less efficient than using Lodash's optimized `intersection` function.

In summary, the benchmark provides a straightforward comparison of three approaches for finding common elements between two arrays: `Array.filter`, `Lodash.intersection`, and `Array.find`. The choice of which approach to use depends on your project requirements, personal preference, and familiarity with each option.

Related benchmarks:

Array filter vs Lodash intersection 2 (version: 0)

Comparing performance of: WARM UP vs Lodash vs Array find

Created: 2 years ago by: Guest

Jump to the latest result

WARM UP

Lodash

Array find

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):