Benchmark: Lodash cloneDeep vs Lodash clone vs Array.slice() vs. Object.assign()

HTML Preparation code:

<script src='https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.20/lodash.min.js'></script>

Script Preparation code:

var arr = ['one', 'two', 'three', {four: 'five'}];

Tests:

Lodash cloneDeep
var myCopy = _.cloneDeep(arr)
Lodash clone
var myCopy = _.clone(arr)
Array.slice()
var myCopy = arr.slice()
Object.assign()
var myCopy = Object.assign([], arr)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Lodash cloneDeep
Lodash clone
Array.slice()
Object.assign()

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 25 days ago):

LLMs can make mistakes. Check important info.

Let's break down the provided JSON and explain what is tested, the options compared, their pros and cons, and other considerations.

**What is being tested?**

The benchmark measures the performance difference between four methods to create a shallow copy of an array: Lodash `cloneDeep`, Lodash `clone`, Array `slice()`, and Object `assign()`.

**Options compared:**

1. **Lodash `cloneDeep`**: Creates a deep copy of the original object, which means all nested properties are recursively cloned.
2. **Lodash `clone`**: Creates a shallow copy of the original object, which means only the top-level properties are copied and not any nested objects.
3. **Array `slice()`**: Returns a new array that contains a subset of elements from the original array, without modifying the original array.
4. **Object `assign()`**: Returns a new object that is a shallow copy of the original object, which means only the top-level properties are copied and not any nested objects.

**Pros and Cons:**

* **Lodash `cloneDeep`**: Pros:
	+ Guarantees a deep copy of the original object.
	+ Suitable for complex data structures with nested objects.
Cons:
	+ Can be slower than other methods due to its recursive cloning process.
* **Lodash `clone`**: Pros:
	+ Faster than `cloneDeep` since it only copies top-level properties.
	+ Still a good choice when you need a shallow copy of an object.
Cons:
	+ May not work as expected if the original object has complex nested structures.
* **Array `slice()`**: Pros:
	+ Fast and efficient, especially for large arrays.
	+ Does not modify the original array.
Cons:
	+ Only creates a shallow copy of the array's elements, not its nested objects.
	+ May not work as expected if you need to preserve certain properties or data structures.
* **Object `assign()`**: Pros:
	+ Fast and efficient, especially for large objects.
	+ Does not modify the original object.
Cons:
	+ Only creates a shallow copy of the top-level properties, not any nested objects.

**Library used:**

The benchmark uses Lodash (a popular JavaScript utility library) for its `cloneDeep` and `clone` functions. The `assign` method is built-in to JavaScript.

**Special JS features or syntax:**

None mentioned in the provided JSON, but it's worth noting that Lodash `cloneDeep` uses a recursive function to clone objects, which might be slower than other methods for very large data structures.

**Alternatives:**

Other alternatives to create a shallow copy of an array or object include:

* Using the spread operator (`...`) in JavaScript (available from ES6 onwards): `const myCopy = [...arr];` or `const myCopy = { ...obj };`
* Utilizing libraries like Immutable.js, which provides a set of immutable data structures and utilities.
* Implementing custom cloning logic using JavaScript's built-in methods, such as `JSON.parse(JSON.stringify(obj))`.

Keep in mind that the performance differences between these alternatives may vary depending on the specific use case and data structure.

Latest run results:

Run details: (Test run date: 2 days ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:132.0) Gecko/20100101 Firefox/132.0

Browser/OS: Firefox 132 on Windows

View result in a separate tab

Test name	Executions per second
Lodash cloneDeep	1229780.8 Ops/sec
Lodash clone	21354164.0 Ops/sec
Array.slice()	44618324.0 Ops/sec
Object.assign()	3808197.0 Ops/sec

Related benchmarks:

Lodash cloneDeep vs Lodash clone vs Array.slice() vs. Object.assign() (version: 0)

For times when a shallow copy is needed, what is the performance difference between these 3 methods.

Comparing performance of: Lodash cloneDeep vs Lodash clone vs Array.slice() vs Object.assign()

Created: 4 years ago by: Guest

Jump to the latest result

Lodash cloneDeep

Lodash clone

Array.slice()

Object.assign()

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 25 days ago):