Benchmark: JavaScript spread operator vs Object.assign vs Lodash.clone(4.17.15)

HTML Preparation code:


<script src='https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.15/lodash.min.js'></script>

Tests:

Using the spread operator
const firstObject = { sampleData: 'Hello world', moreData: 'foo bar' } const finalObject = { ...firstObject };
Using Object.assign
const firstObject = { sampleData: 'Hello world', moreData: 'foo bar' } const finalObject = Object.assign(firstObject);
Using lodash.clone
const firstObject = { sampleData: 'Hello world', moreData: 'foo bar' } const finalObject = _.clone(firstObject);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Using the spread operator
Using Object.assign
Using lodash.clone

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 4 years ago)

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Ubuntu Chromium/83.0.4103.97 Chrome/83.0.4103.97 Safari/537.36

Browser/OS: Chromium 83 on Ubuntu

View result in a separate tab

Test name	Executions per second
Using the spread operator	71989656.0 Ops/sec
Using Object.assign	8307345.0 Ops/sec
Using lodash.clone	1992660.5 Ops/sec

Autogenerated LLM Summary (model llama3.2:3b, generated one month ago):

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and explain what is being tested, compared, and their pros/cons.

**Benchmark Overview**

The provided benchmark compares the performance of three approaches to create a shallow copy of an object:

1. **Spread Operator**: Using the `...` syntax to spread the properties of the original object into a new object.
2. **Object.assign()**: Using the `Object.assign()` method to create a shallow copy of the original object.
3. **Lodash.clone()**: Using the `lodash.clone()` function from the Lodash library to create a shallow clone of the original object.

**Options Comparison**

The benchmark compares the performance of these three approaches on a test case with two properties: `sampleData` and `moreData`. The approach being tested is the way to create a new object that inherits the properties of the original object.

**Pros/Cons of Each Approach:**

1. **Spread Operator**:
	* Pros:
		+ Simple and concise syntax
		+ Fast and efficient (O(1) time complexity)
	* Cons:
		+ May not work correctly with nested objects or arrays
		+ Does not create a deep copy, only a shallow one
2. **Object.assign()**:
	* Pros:
		+ Works well with nested objects and arrays
		+ Can be used to merge multiple objects into one
	* Cons:
		+ May be slower than the spread operator due to its overhead (O(n) time complexity)
3. **Lodash.clone()**:
	* Pros:
		+ Guarantees a deep copy, even with nested objects and arrays
		+ Can handle more complex object structures, like cyclic references
	* Cons:
		+ Requires an external library (Lodash) to be included
		+ May introduce additional overhead compared to the spread operator

**Other Considerations**

When choosing between these approaches, consider the specific requirements of your use case:

* If you only need a shallow copy and don't mind the spread operator's limitations, it may be the best choice.
* If you need a deep copy or want to handle complex object structures, Lodash.clone() is a safer bet.
* If performance is critical, using Object.assign() might be a good compromise between speed and functionality.

**Library: Lodash**

Lodash is a popular JavaScript library that provides various utility functions for tasks like array manipulation, string manipulation, and more. The `lodash.clone()` function is specifically designed to create deep copies of objects and arrays. It's included in the benchmark as part of the test case setup code.

**Special JS Feature/Syntax: Spread Operator**

The spread operator (`...`) is a new feature introduced in ECMAScript 2018 (ES2018). It allows you to spread the properties of an object into a new object, creating a shallow copy. This syntax is concise and expressive but requires support for modern browsers or Node.js versions that include ES2018+ support.

In summary, the benchmark compares three approaches to create a shallow copy of an object: the spread operator, Object.assign(), and Lodash.clone(). Each approach has its pros and cons, and choosing the right one depends on your specific use case and requirements.

Related benchmarks:

JavaScript spread operator vs Object.assign vs Lodash.clone(4.17.15) (version: 0)

Comparing performance of: Using the spread operator vs Using Object.assign vs Using lodash.clone

Created: 4 years ago by: Guest

Jump to the latest result

Using the spread operator

Using Object.assign

Using lodash.clone

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated one month ago):