Let's break down the provided benchmark and its results.

What is tested?

The benchmark compares three different approaches to find if an array contains a specific value:

1. array.indexOf('sausage') !== 1: This method uses the indexOf function to search for the index of the specified element in the array. If the element is found, it returns its index; otherwise, it returns -1. The comparison with !== 1 checks if the element is present at the expected position.
2. array.includes('sausage'): This method uses the includes function to check if the specified element is present in the array.
3. array.findIndex(v => v === 'sausage'): This method uses the findIndex function with a callback function to find the index of the first occurrence of the specified element.

Options compared

The benchmark compares these three approaches:

1. indexOf: A built-in JavaScript method that searches for the index of a specific value in an array.
2. includes: A more recent addition to the JavaScript standard library, introduced in ECMAScript 2015 (ES6), which provides a simpler and more efficient way to check if an array contains a specified value.
3. findIndex: Another built-in JavaScript method that finds the index of the first occurrence of a specific value in an array.

Pros and cons

1. indexOf:
   • Pros: Widely supported, well-documented, and easy to use.
   • Cons: Can be slower than includes for large arrays, as it uses linear search.
2. includes:
   • Pros: Faster and more efficient than indexOf, especially for large arrays. It also provides a simpler syntax.
   • Cons: Less widely supported in older browsers or environments (pre-ES6).
3. findIndex:
   • Pros: More flexible and powerful than indexOf, as it allows searching from the beginning of the array.
   • Cons: Can be slower than includes for simple searches, as it iterates over the entire array.

Library usage

The benchmark uses the popular JavaScript utility library Lodash, version 4.17.5, which provides a findIndex function. Lodash is widely used and well-maintained, making it a good choice for this benchmark.

Special JS features or syntax

None mentioned in this specific benchmark. However, some older browsers might not support modern JavaScript features like includes.

Other alternatives

For comparing performance, other approaches could include:

1. Using forEach or map to iterate over the array and check each element manually.
2. Using a library like Underscore.js, which provides a similar set of utility functions to Lodash.
3. Implementing custom search algorithms, such as binary search for large arrays.

Keep in mind that these alternatives might not be as efficient or well-documented as the standard methods and libraries used in this benchmark.