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

Benchmark Overview

The benchmark is designed to compare the performance of two approaches for creating an array with unique values: Array.reduce combined with Array.indexOf (using JavaScript) and Lodash's uniq function.

Script Preparation Code

The script preparation code generates a random array of 100 unique integers using the Array.from method. This array is used as input for both test cases.

var itemsCount = 1e2; // 100
var items = Array.from({ length: itemsCount }, () => Math.floor(Math.random() * itemsCount));

Html Preparation Code

The HTML preparation code includes the Lodash library, which is used in one of the test cases.

<script src="https://cdn.jsdelivr.net/npm/lodash@4.17.5/lodash.min.js"></script>

Test Cases

There are two test cases:

Test Case 1: JavaScript Array.reduce/Array.indexOf

This test case uses the reduce method in combination with Array.indexOf. The idea is to iterate over the array and add each item to the result array if it's not already present.

items.reduce((list, item) => list.indexOf(item) > -1 ? list : [...list, item], []);

Pros:

• Native JavaScript implementation, which might be optimized for performance.
• Easy to understand and implement.

Cons:

• The indexOf method can lead to a linear search in the worst case (when an item is not found), resulting in a time complexity of O(n).
• This approach may be slower than using a more efficient algorithm like Lodash's uniq.

Test Case 2: Lodash Uniq

This test case uses Lodash's uniq function to create an array with unique values.

_.uniq(items);

Pros:

• More efficient and optimized implementation compared to the JavaScript approach.
• Lodash's implementation might be faster due to its use of specialized algorithms or data structures.

Cons:

• Requires including the Lodash library, which may add overhead.
• Might not be as easy to understand for those without familiarity with Lodash.

Other Considerations

• The benchmark is executed on a Chrome 100 browser on a Linux desktop platform. The results might vary depending on the environment and browser version used.
• The ExecutionsPerSecond value indicates the number of times each test case was executed per second, which can affect the overall performance measurement.

Alternative Approaches

Other approaches to create an array with unique values could include:

• Using a Set data structure (native JavaScript): new Set(items).values();
• Utilizing a library like Ramda or Underscore.js for more functional programming-inspired solutions.
• Implementing a custom algorithm using bitwise operations or other optimization techniques.

Keep in mind that the performance of these alternatives might vary, and it's essential to test and benchmark them to determine their suitability for your specific use case.