Benchmark: JavaScript spread operator vs Object.assign performanceeww

Script Preparation code:

var bigObject = {}
for(let i = 0; i < 3000; i++){
 bigObject[i] = {test: "gjiesj", tsdl: "dkfosjfosdjf"} 
}

Tests:

Using the spread operator
const secondObject = { moreData: 'foo bar' } const finalObject = { ...bigObject, ...secondObject };
Using Object.assign
const secondObject = { moreData: 'foo bar' } const finalObject = Object.assign(bigObject, secondObject);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

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

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

This benchmark does not have any results yet. Be the first one to run it!

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

LLMs can make mistakes. Check important info.

Let's dive into explaining the provided benchmark and its results.

**Benchmark Definition**

The benchmark is designed to compare the performance of two approaches: using the JavaScript spread operator (`...`) and `Object.assign()` for merging objects.

**Script Preparation Code**

The script preparation code creates a large object `bigObject` with 3000 properties, each containing two key-value pairs. This object will be used as a baseline for the benchmark.

**Html Preparation Code**

There is no HTML preparation code provided, which means that only JavaScript performance is being measured and compared.

**Individual Test Cases**

There are two test cases:

1. **Using the spread operator**: The first test case uses the spread operator (`...`) to merge `bigObject` with another object `secondObject`. This approach is expected to be more concise and expressive, but may incur additional overhead due to the need for parsing and evaluation.
2. **Using Object.assign()**: The second test case uses `Object.assign()` to merge `bigObject` with `secondObject`. This approach is more traditional and widely used, but may require more boilerplate code and be less efficient than the spread operator.

**Pros and Cons of Each Approach**

1. **Using the spread operator**:
	* Pros: More concise and expressive, can reduce code duplication.
	* Cons: May incur additional overhead due to parsing and evaluation, can lead to slower performance in some cases.
2. **Using Object.assign()**:
	* Pros: Widely supported, well-established, and efficient for large objects.
	* Cons: Requires more boilerplate code, can be less expressive.

**Other Considerations**

* Both approaches assume that the source object (`bigObject`) is a large object with many properties, which may not be representative of typical use cases where objects are smaller and simpler.
* The benchmark does not account for any potential side effects or changes to the original `bigObject` during the merge process.

**Library and Special JS Features**

There are no libraries mentioned in the benchmark, but it uses a common JavaScript feature: destructuring assignment (`...`). This syntax is supported by most modern browsers and Node.js environments.

**Other Alternatives**

If you're interested in exploring alternative approaches to merging objects, here are a few options:

* **Lodash.merge()**: A popular utility library that provides an efficient and expressive way to merge objects.
* **ES6 Object Spread Syntax (Shorthand)**: An older syntax for merging objects, which is still supported by most browsers and Node.js environments.

Overall, the benchmark provides a good starting point for understanding the performance differences between using the spread operator and `Object.assign()`. However, keep in mind that the results may not be representative of all use cases, and further investigation may be necessary to determine the best approach for your specific needs.

Related benchmarks:

JavaScript spread operator vs Object.assign performanceeww (version: 0)

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

Created: 7 years ago by: Guest

Jump to the latest result

Using the spread operator

Using Object.assign

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

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