Benchmark: reduce,includes vs map,uniq

HTML Preparation code:

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

Tests:

a
var l = [1, 2, 3, 4, 5, 6, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7]; var l = l.map(e => e); return _.uniq(l);
b
var l = [1, 2, 3, 4, 5, 6, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7]; return l.reduce((sum, e) => { if (sum.includes(e)) { return sum; } return [...sum, e]; }, []);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
a
b

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 dive into the explanation of the provided JavaScript benchmark.

**Benchmark Definition**

The benchmark is designed to compare two approaches for removing duplicates from an array: using `map` and `uniq`, versus using `reduce` with a custom implementation that checks for existence in the accumulator using `includes`.

**Script Preparation Code**

The script preparation code includes a reference to the Lodash library, which provides the `_uniq` function used in one of the benchmark cases.

**Individual Test Cases**

There are two test cases:

1. **Test Case "a"**: This test case uses the `map` and `uniq` approach from Lodash. It creates an array with duplicates and then maps each element to itself, finally removing duplicates using `_uniq`.
2. **Test Case "b"**: This test case uses a custom implementation of `reduce` that checks for existence in the accumulator using `includes`. The idea is to add elements to the accumulator only if they are not already present.

**Options Compared**

The two options being compared are:

1. **Lodash's `map` and `uniq` approach**: This approach is concise and efficient, but relies on an external library.
2. **Custom `reduce` implementation with `includes`**: This approach is more control-oriented, allowing the developer to fine-tune the logic for removing duplicates.

**Pros and Cons**

1. **Lodash's `map` and `uniq` approach**:
	* Pros:
		+ Concise and easy to read
		+ Leverages a well-tested and widely adopted library (Lodash)
	* Cons:
		+ Requires an external dependency (Lodash)
2. **Custom `reduce` implementation with `includes`**:
	* Pros:
		+ More control over the logic for removing duplicates
		+ No external dependencies required
	* Cons:
		+ May be less concise and more verbose than the Lodash approach
		+ Requires a deeper understanding of the `includes` method's behavior

**Other Considerations**

When choosing between these two approaches, consider the following factors:

1. **Performance**: The custom implementation with `includes` may have performance advantages if the dataset is large or the duplicates are relatively sparse.
2. **Code readability and maintainability**: The Lodash approach is often considered more readable and maintainable due to its concise syntax.
3. **Library dependencies**: If you're working on a project that requires specific libraries, using Lodash might be necessary.

**Alternative Approaches**

Other approaches for removing duplicates from an array include:

1. **Using `Set`**: Converting the array to a Set (if supported) can automatically remove duplicates due to the Set's immutability and duplicate detection behavior.
2. **Sorting and filtering**: Sorting the array and then filtering out consecutive duplicates can also achieve the desired result.

However, these approaches may not be as efficient or concise as the Lodash approach or the custom `reduce` implementation with `includes`.

I hope this explanation helps software engineers understand the nuances of JavaScript benchmarking!

Related benchmarks:

reduce,includes vs map,uniq (version: 1)

Comparing performance of: a vs b

Created: 4 years ago by: Registered User

Jump to the latest result

a

b

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):