I'd be happy to explain the provided benchmark.

What is tested?

The provided benchmark measures the performance difference between two approaches: _.isEqual from the Lodash library and a simple string comparison using JSON.stringify. The test creates two objects, window.foo and window.bar, with identical properties but different types (number vs. string). It then checks if these two objects are equal using both methods.

Options compared

There are two options being compared:

1. _.isEqual(window.foo, window.bar): This method uses the Lodash library to compare the two objects.
2. JSON.stringify(window.foo) === JSON.stringify(window.bar): This is a simple string comparison where the JSON.stringify function converts both objects into strings and then compares them.

Pros and Cons

1. _.isEqual(window.foo, window.bar):
   • Pros: Efficient and fast since it uses a specialized algorithm for comparing objects.
   • Cons: Requires loading an additional library (Lodash), which may add overhead to the benchmark.
2. JSON.stringify(window.foo) === JSON.stringify(window.bar):
   • Pros: Lightweight and easy to implement, as it only relies on built-in JavaScript functions.
   • Cons: May be slower due to the overhead of converting objects to strings and comparing them.

Library

The Lodash library is a popular utility library for JavaScript that provides a wide range of functions for tasks such as string manipulation, array operations, and object comparison. In this benchmark, _.isEqual is used to compare two objects efficiently.

Special JS feature or syntax

There are no special JS features or syntax being tested in this benchmark. The focus is on comparing the performance of two different approaches to equality checking.

Other alternatives

If you wanted to implement a custom equality checker without relying on Lodash, you could use a simple recursive function that compares each property of the objects:

function equal(a, b) {
  if (typeof a !== typeof b) return false;
  for (let key in a) {
    if (a[key] !== b[key]) return false;
  }
  return true;
}

Another approach could be to use the Object.keys method to compare the properties of the objects:

function equal(a, b) {
  const keysA = Object.keys(a);
  const keysB = Object.keys(b);
  if (keysA.length !== keysB.length) return false;
  for (let i = 0; i < keysA.length; i++) {
    if (a[keysA[i]] !== b[keysB[i]]) return false;
  }
  return true;
}

Keep in mind that these custom implementations may not be as efficient or reliable as using a well-tested library like Lodash.