Benchmark: extend vs cloneDeep vs JSON.*

HTML Preparation code:

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/2.4.1/lodash.min.js"></script>

Script Preparation code:

var myObj = {
    "name":"John",
    "age":30,
    "cars": {
        "car1":"Ford",
        "car2":"BMW",
        "car3":"Fiat"
    }
 }

Tests:

extend
let a = 'a'
cloneDeep
let a = _.cloneDeep(myObj)
JSON.*
let a = JSON.parse(JSON.stringify(myObj))

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
extend
cloneDeep
JSON.*

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 29 days ago):

LLMs can make mistakes. Check important info.

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

**Benchmark Overview**

The benchmark measures the performance of three approaches to copy or extend an object in JavaScript:

1. `extend` (using the `Object.assign()` method)
2. `cloneDeep` (using Lodash's `cloneDeep` function)
3. `JSON.*` (using `JSON.parse(JSON.stringify(myObj))`)

**Options Comparison**

Here's a comparison of the three approaches and their pros and cons:

* **extend (Object.assign())**:
	+ Pros: Simple, widely supported, and efficient for shallow copies.
	+ Cons: Can create new objects, which may incur memory allocation overhead. Not suitable for deep object copies or when preserving prototype chains is important.
* **cloneDeep (Lodash)**:
	+ Pros: Designed specifically for deep cloning objects, handling circular references, and preserving prototype chains. More efficient than `extend` for large or complex objects.
	+ Cons: Requires Lodash library, which may add overhead depending on the size of the benchmark. May not be suitable for very small objects due to library overhead.
* **JSON.* (JSON.parse(JSON.stringify(myObj)))**:
	+ Pros: Simple and widely supported. Preserves prototype chains and handles circular references.
	+ Cons: Inefficient for large or complex objects, as it creates a new object graph by recursively parsing the original object's properties. May not be suitable for very small objects due to the overhead of creating a new object.

**Library: Lodash**

Lodash is a popular utility library that provides various functions for working with JavaScript data structures, including arrays, objects, and more. The `cloneDeep` function is specifically designed to create deep, recursive copies of objects, handling circular references and preserving prototype chains.

**Special JS Feature/Syntax**

There are no special features or syntaxes being tested in this benchmark. All tests use standard JavaScript syntax and semantics.

**Other Alternatives**

Other alternatives for creating deep object copies include:

* Using the `lodash.cloneDeep` function with Lodash (which is already used in this benchmark)
* Implementing a custom recursive clone function
* Using a library like `deepcopy` or `objclone`
* Creating a new object and manually copying properties using `Object.assign()` or other methods

Keep in mind that each alternative has its own trade-offs, such as performance overhead, library dependencies, or code complexity. The benchmark provides a useful comparison of the three approaches, but users may want to explore other options depending on their specific requirements and constraints.

Latest run results:

Run details: (Test run date: 5 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/75.0.3770.145 Safari/537.36 Vivaldi/2.6.1566.49

Browser/OS: Chrome 75 on Windows

View result in a separate tab

Test name	Executions per second
extend	86661840.0 Ops/sec
cloneDeep	608902.2 Ops/sec
JSON.*	212874.6 Ops/sec

Related benchmarks:

extend vs cloneDeep vs JSON.* (version: 0)

Comparing performance of: extend vs cloneDeep vs JSON.*

Created: 6 years ago by: Guest

Jump to the latest result

extend

cloneDeep

JSON.*

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 29 days ago):