Benchmark: JavaScript sprea 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:

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

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**Benchmark Overview**

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

**Test Cases**

There are two test cases:

1. **Using the spread operator**: This test case uses the spread operator to merge two objects, `firstObject` and `secondObject`, into a single object, `finalObject`. The syntax is: `{ ...firstObject, ...secondObject }`.
2. **Using Object.assign()**: This test case uses the `Object.assign()` method to merge two objects, `firstObject` and `secondObject`, into a single object, `finalObject`.

**Options Compared**

The benchmark compares the performance of these two approaches:

* Spread operator (`...`)
* `Object.assign()`

**Pros and Cons of Each Approach**

1. **Spread Operator (`...`)**
	* Pros:
		+ More concise and readable syntax
		+ Works with objects of any shape (nested objects, arrays, etc.)
		+ No explicit method call required
	* Cons:
		+ May have performance overhead due to the creation of a new object
		+ May not be supported in older browsers or environments
2. **Object.assign()**
	* Pros:
		+ Widely supported and well-established method
		+ Can handle objects of any shape (nested objects, arrays, etc.)
		+ Can be used for other purposes beyond object merging (e.g., assigning properties to an object)
	* Cons:
		+ Requires explicit method call
		+ May have performance overhead due to the creation of a new object

**Other Considerations**

When choosing between these two approaches, consider the following factors:

* Readability and maintainability: The spread operator provides a more concise and readable syntax.
* Performance: Both approaches may have performance overhead, but the spread operator's syntax may lead to better cache locality and fewer function calls.
* Browser support: Ensure that the approach you choose is supported by the target browsers.

**Library/Function Used**

None of these test cases use any libraries or external functions beyond built-in JavaScript features.

**Special JS Feature/Syntax**

The benchmark uses the spread operator (`...`), which is a relatively recent feature introduced in ECMAScript 2018. This syntax allows for more concise and readable object merging.

**Alternative Approaches**

Other approaches to merge objects in JavaScript include:

* Using a library like Lodash's `merge()` function
* Using a utility function, such as `object.assign()` wrapper functions (e.g., using `Object.create()`)
* Using a different data structure, such as arrays or JSON strings

The benchmark does not test these alternative approaches.

Related benchmarks:

JavaScript sprea vs Object.assign performance (version: 0)

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

Created: 3 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):