Let's break down what's being tested in the provided JSON.

Benchmark Purpose: The benchmark compares the performance of two approaches for equality comparison: using Lodash's isEqual function and using JSON.stringify. The test focuses on shallow array comparisons, specifically when the comparison is not equal.

Options Compared:

1. Lodash.isEqual: This approach uses the Lodash library to compare the arrays. It's a higher-order function that takes two arguments and returns a boolean indicating whether they are equal.
2. JSON.stringify Equality Comparison: This approach uses the JSON.stringify method on both arrays, comparing the resulting strings for equality. The idea is to convert the arrays to strings and then compare them.

Pros and Cons:

1. Lodash.isEqual
   • Pros:
     • More efficient in terms of execution time (as shown by the benchmark results).
     • Reduces the chance of typos or other errors when writing custom comparison code.
   • Cons:
     • Requires including an additional library (Lodash) in the test environment.
2. JSON.stringify Equality Comparison
   • Pros:
     • Only requires the inclusion of the JSON object, which is a built-in part of most JavaScript engines.
   • Cons:
     • May be slower due to the conversion process and potential issues with string comparison (e.g., comparing arrays as strings).
     • More prone to errors if not done correctly.

Library: The JSON.stringify method converts its argument(s) into a JSON string, which can be compared for equality. In this benchmark, it's used to compare the string representations of two shallow arrays.

Special JS Feature/Syntax: There is no special JavaScript feature or syntax mentioned in the benchmark. However, using JSON.stringify for comparison relies on the browser implementing it correctly and efficiently.

Benchmark Results: The latest benchmark results show that Lodash's isEqual function outperforms the JSON.stringify approach in terms of execution time (measured in executions per second). This suggests that the custom implementation is slower due to the overhead of converting the arrays to strings and comparing them.

Other Alternatives:

1. Array.prototype.every(): This method checks if every element in an array passes a test. It can be used for equality comparison by using every() with a callback function.
2. Array.prototype.some(): Similar to every(), but returns as soon as it finds at least one element that doesn't pass the test.
3. Custom implementation: A custom implementation could use loops or recursion to compare elements of two arrays. However, this approach is often slower and more prone to errors than using a library function like Lodash's isEqual.