Benchmark: JavaScript spread operator vs Object.assign performance

Tests:

Using the spread operator
const firstObject = { sampleData: 'Hello world' } const secondObject = { moreData: 'foo bar' } const finalObject = { ...firstObject, ...secondObject };
Using Object.assign
const firstObject = { sampleData: 'Hello world' } const secondObject = { moreData: 'foo bar' } const finalObject = Object.assign({}, firstObject, 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 llama3.1:latest, generated one year ago):

LLMs can make mistakes. Check important info.

Let's dive into what's being tested in this benchmark.

**What is being tested?**

The benchmark is comparing the performance of two different approaches to merge multiple objects into one:

1. Using the JavaScript spread operator (`...`) to merge `firstObject` and `secondObject` into `finalObject`.
2. Using the `Object.assign()` method to merge `firstObject` and `secondObject` into `finalObject`.

**What options are compared?**

The two test cases compare the performance of:

1. The spread operator (`...`) approach.
2. The `Object.assign()` method approach.

**Pros/Cons of each approach:**

1. **Spread Operator (`...`):**
	* Pros:
		+ More concise and readable code.
		+ Can be used to merge multiple objects in a single expression.
	* Cons:
		+ May create unnecessary intermediate arrays or objects, which can impact performance.
2. **Object.assign():**
	* Pros:
		+ Creates a new object by copying properties from one or more source objects.
		+ Can be more efficient than the spread operator for large datasets.
	* Cons:
		+ Requires multiple function calls (one per source object).
		+ May not be as concise as the spread operator.

**Other considerations:**

1. **Library usage:** There is no library used in these test cases.
2. **Special JS feature or syntax:** The only special JS feature used here is the spread operator (`...`), which is a standard JavaScript feature introduced in ECMAScript 2015 (ES6).
3. **Alternatives:**
	* You could also use the `Object.create()` method to merge objects, but this approach is less common and may have performance implications.
	* Another alternative is to use a library like Lodash or Underscore.js, which provide optimized merging functions.

**Latest benchmark results:**

The test results show that the spread operator (`...`) approach outperforms the `Object.assign()` method approach in this particular scenario. However, it's essential to note that performance differences may vary depending on the specific use case and environment.

I hope this explanation helps you understand what's being tested in this benchmark!

Related benchmarks:

JavaScript spread operator vs Object.assign performance (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 llama3.1:latest, generated one year ago):