Benchmark: JavaScript spread operator vs Object.assign performance 13

Script Preparation code:

var firstObject = { sampleData: 'Hello world' }
var secondObject = { moreData: 'foo bar' }

Tests:

Using the spread operator
const finalObject = { ...firstObject, ...secondObject };
Using Object.assign
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 llama3.2:3b, generated one year ago):

LLMs can make mistakes. Check important info.

Let's break down what's being tested in this benchmark.

**Benchmark Overview**

The test measures the performance of two different ways to merge two objects into one: using the JavaScript spread operator (`...`) and using the `Object.assign()` method.

**Options Compared**

We have two options:

1. **Using the spread operator**: This approach uses the `...` operator to merge the properties of two objects (`firstObject` and `secondObject`) into a new object (`finalObject`). The syntax is: `const finalObject = { ...firstObject, ...secondObject };`
2. **Using Object.assign()**: This approach uses the `Object.assign()` method to merge the properties of two objects into a new object. The syntax is: `const finalObject = Object.assign({}, firstObject, secondObject);`

**Pros and Cons**

Here are some pros and cons of each approach:

* **Using the spread operator**:
	+ Pros:
		- More concise and readable syntax
		- Can be used with multiple objects in a single line
		- Less error-prone than `Object.assign()`
	+ Cons:
		- May not work as expected if one of the objects is null or undefined
		- Can lead to unnecessary copying of properties if not used carefully
* **Using Object.assign()**:
	+ Pros:
		- More predictable behavior, especially with multiple objects
		- Can handle null or undefined values more robustly
	+ Cons:
		- Less concise and less readable syntax
		- May lead to typos or errors if not used carefully

**Library and Purpose**

In this benchmark, no libraries are used. However, it's worth noting that `Object.assign()` is a built-in method in JavaScript.

**Special JS Feature/Syntax**

There isn't any special JavaScript feature or syntax being tested in this benchmark.

**Other Alternatives**

If you need to merge objects, there are other alternatives:

* **Destructuring**: You can use destructuring assignment (e.g., `const { ... } = obj`) to extract properties from an object.
* **Object.create()**: You can create a new object using `Object.create()` and then assign properties to it.

However, these alternatives might not be suitable for all scenarios, especially when dealing with complex objects or performance-critical code.

Related benchmarks:

JavaScript spread operator vs Object.assign performance 13 (version: 0)

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

Created: 2 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):