Benchmark: Lodash Union vs Spread Operator

HTML Preparation code:

<script src='https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.20/lodash.min.js'></script>

Script Preparation code:

var arr1 = new Array(1000).fill(0);
var arr2 = new Array(1000).fill(1);

Tests:

Spread Operator
[...arr1, ...arr2]
Lodash union
_.union(arr1, arr2)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Spread Operator
Lodash union

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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I'd be happy to explain what's being tested in the provided benchmark.

**What is being tested?**

The benchmark compares two approaches to create a new array by combining two existing arrays: using the spread operator (`[...arr1, ...arr2]`) and using Lodash's `union` function (`_.union(arr1, arr2)`).

**Options compared**

Two options are being compared:

1. **Spread Operator**: This method uses the `...` operator to create a new array by spreading the elements of two arrays.
2. **Lodash Union**: This method uses the Lodash library's `union` function to create a new array containing all unique elements from two arrays.

**Pros and Cons**

**Spread Operator:**

Pros:

* Simple and concise syntax
* Fast execution, as it only involves a simple concatenation operation
* No additional dependencies required (built-in to JavaScript)

Cons:

* Can be slower than the Lodash approach for very large arrays, due to the overhead of creating a new array.
* May not perform well if the two input arrays are of different lengths.

**Lodash Union:**

Pros:

* Efficient and optimized implementation, which can outperform the spread operator for large arrays.
* Handles cases where the two input arrays have different lengths.

Cons:

* Requires an external library dependency (Lodash).
* More complex syntax than the spread operator.

**Other considerations**

Both approaches assume that the input arrays `arr1` and `arr2` are already created and contain elements to be combined. The benchmark uses JavaScript arrays as the input data structures.

**Library: Lodash**

The `union` function from Lodash is used in the benchmark, which provides a convenient way to combine arrays while ignoring duplicates.

**Special JS feature or syntax (not applicable)**

There are no special JavaScript features or syntaxes being tested in this benchmark.

**Other alternatives**

If you were to implement your own array union logic, you could consider using:

1. **Array.prototype.concat()**: A simple and straightforward approach that involves concatenating the two arrays.
2. **Set data structure**: Using sets can provide an efficient way to combine arrays by automatically eliminating duplicates.

Keep in mind that implementing these alternatives would likely be slower than using the Lodash `union` function or the spread operator, especially for large datasets.

Related benchmarks:

Lodash Union vs Spread Operator (version: 0)

Comparing performance of: Spread Operator vs Lodash union

Created: 4 years ago by: Guest

Jump to the latest result

Spread Operator

Lodash union

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):