Let's break down the provided benchmark and explain what's being tested.

Benchmark Overview

The benchmark is designed to test the performance of JavaScript filters, specifically comparing two approaches: using the filter() method with an arrow function and using the includes() method with an array literal.

Script Preparation Code

The script preparation code defines a variable options containing six numbers:

var options = [1, 2, 3, 4, 5, 6];

This script is executed before running each test case. The purpose of this code is to provide a common input set for both test cases.

Html Preparation Code

The html preparation code is empty (null), which means that no HTML-related setup or cleanup is performed during the benchmarking process.

Test Cases

There are two test cases:

1. filter: This test case defines a function as follows:

return options.filter((option) => option !== 1 && option !== 2);

This function uses the filter() method with an arrow function to create a new array containing only the elements from options that are not equal to 1 or 2.

2. includes: This test case defines a function as follows:

return options.filter((option) => ![1,2].includes(option));

This function uses the filter() method with an arrow function and the includes() method to create a new array containing only the elements from options that are not present in the array [1, 2].

Library and Features

In this benchmark, no specific JavaScript library is used. However, some general features are utilized:

• Arrow functions: Both test cases use arrow functions ((option) => ...) as a concise way to define small anonymous functions.
• Filter() method: This method is used in both test cases to create new arrays based on conditions.

Alternative Approaches

If you were to reimplement these benchmark tests, here are alternative approaches to consider:

1. Using forEach() instead of filter(): You could use a loop (forEach()) to iterate over the array and push elements to a result array that meet the condition.

return options.filter((option) => option !== 1 && option !== 2);
// equivalent using forEach()
const result = [];
options.forEach((option) => {
  if (option !== 1 && option !== 2) {
    result.push(option);
  }
});

However, this approach would likely have a slower execution time than the filter() method.

2. Using Map or Set instead of Array: You could use a Map or Set to store unique values and then filter them using the same conditions.

// equivalent using Map
const map = new Map();
options.forEach((option) => {
  if (option !== 1 && option !== 2) {
    map.set(option, true);
  }
});
return [...map.keys()];

However, this approach would likely have a slower execution time than the filter() method due to the overhead of creating and manipulating Maps/Sets.

3. Using native Array.prototype.some() instead of includes(): You could use the some() method to check if any element in the array matches a certain condition.

return options.filter((option) => !options.includes(option));
// equivalent using some()
const result = [];
options.forEach((option) => {
  if (!options.some((o) => o === option)) {
    result.push(option);
  }
});

However, this approach would likely have a slower execution time than the includes() method due to the overhead of calling some() on each element.

These alternative approaches can provide insight into how different methods perform under various conditions. However, in general, the filter() method remains one of the most efficient ways to filter arrays in JavaScript.