Benchmark: _.compact vs .filter(x => x !== undefined)

HTML Preparation code:


<script src='https://cdn.jsdelivr.net/npm/lodash@4.17.10/lodash.min.js'></script>

Script Preparation code:

var withUndefined = new Array(10000).fill(undefined)
for (let i = 0; i < withUndefined.length; i += 2) withUndefined[i] = 'not undefined'

Tests:

_
_.compact(withUndefined)
filter
withUndefined.filter(x => x !== undefined)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
_
filter

Fastest: N/A

Slowest: N/A

Latest run results:

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

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Let's break down the provided benchmark definition and test cases.

**What is being tested?**

The two individual test cases are measuring the performance of two different approaches to remove `undefined` values from an array:

1. **_.compact(withUndefined)**
2. **withUndefined.filter(x => x !== undefined)**

These tests compare the performance of the two methods in removing `undefined` values from the array.

**Options compared**

The options being compared are:

* **_.compact()**: a utility function from the Lodash library that removes elements equal to zero, null, and undefined. It's designed to compact an array by eliminating consecutive elements with a specified value.
* **Array.prototype.filter()**: a native JavaScript method that creates a new array with all elements that pass a test implemented by a provided function.

**Pros and cons of each approach**

1. **_.compact()**
	* Pros:
		+ Compact and efficient implementation
		+ Designed specifically for this use case, minimizing overhead
	* Cons:
		+ Requires Lodash library to be included in the test environment
		+ May have additional dependencies or overhead due to its specific implementation
2. **Array.prototype.filter()**
	* Pros:
		+ Native JavaScript method, no external dependencies required
		+ Can be more straightforward to implement and optimize
	* Cons:
		+ May require manual implementation of the callback function, adding complexity
		+ Can be slower due to the overhead of creating a new array

**Library usage**

The Lodash library is used in this benchmark definition. Specifically, it provides the `_.compact()` method, which is being compared to the native `Array.prototype.filter()` method.

**Special JS feature or syntax**

There are no special JavaScript features or syntax mentioned in this benchmark definition. The focus is on comparing two different approaches to remove `undefined` values from an array.

**Alternative implementations**

Other alternatives for removing `undefined` values from an array could include:

* Using the native `Array.prototype.map()` method with a callback function that checks for `undefined` and returns a default value (e.g., null)
* Utilizing a more complex implementation, such as using `reduce()` or `forEach()`, to achieve the same result

However, these alternatives would likely be slower and more complex than the two methods being compared in this benchmark definition.

I hope this explanation helps!

Related benchmarks:

_.compact vs .filter(x => x !== undefined) (version: 0)

Comparing performance of: _ vs filter

Created: 4 years ago by: Guest

Jump to the latest result

_

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):