Overview

The provided benchmark measures the performance of three methods for creating a copy of an object in JavaScript: Lodash's cloneDeep, Mozilla's structuredClone (a native implementation), and JSON.parse(JSON.stringify(obj)). The goal is to determine which method is the fastest.

Methods Compared

1. Lodash's cloneDeep: This method uses a recursive approach to create a deep copy of an object, which means it also copies nested objects.
2. Mozilla's structuredClone (native): This is a native implementation in JavaScript, introduced in ECMAScript 2022, that creates a shallow copy of an object by creating a new instance with the same value types and property names as the original object.
3. JSON.parse(JSON.stringify(obj)): This method uses JSON serialization to create a copy of an object. It serializes the object to a string using JSON.stringify, then deserializes it back into an object using JSON.parse.

Pros and Cons

• Lodash's cloneDeep:
  • Pros: Recursively creates deep copies, handles complex objects with nested objects.
  • Cons: Can be slower due to the recursive approach and potential overhead of cloning entire objects.
• Mozilla's structuredClone (native):
  • Pros: Fast, efficient, and optimized for modern JavaScript environments.
  • Cons: Only creates shallow copies, which may not be suitable for all use cases.
• JSON.parse(JSON.stringify(obj)):
  • Pros: Simple, lightweight, and widely supported.
  • Cons: Can create unexpected behavior if the object contains cyclic references or certain primitive values (e.g., NaN, Infinity).

Library and Purpose

In this benchmark, Lodash is a popular JavaScript utility library that provides various functions for tasks like array manipulation, string manipulation, and more. The cloneDeep function is part of Lodash's deep object manipulation module.

Special JS Features or Syntax

There are no special JS features or syntax used in these benchmarks. They focus on the performance comparison of three distinct methods for creating object copies.

Other Alternatives

If you need to create a copy of an object, other alternatives include:

• Object.assign(): Creates a shallow copy of an object by copying all own enumerable properties.
• Array.prototype.slice() or Array.prototype.reduce(): Can be used to create a shallow copy of an array (or an object that is converted to an array).
• Libraries like Immutable.js: Provides immutable data structures and methods for creating copies.

Keep in mind that the choice of method depends on your specific use case, performance requirements, and personal preference.