Benchmark: JavaScript spread operator vs Object.assign performance 2

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 llama3.2:3b, 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 benchmark compares the performance of two approaches to merge two JavaScript objects:

1. Using the spread operator (`...`)
2. Using `Object.assign()` with an empty object as the target (`{}`)

**Options Compared**

* The spread operator (`...`) is a new way of merging objects introduced in ECMAScript 2018 (ES2018). It allows you to merge two or more objects into one using the syntax `object1 [...object2]`.
* `Object.assign()` is an older method for merging objects, which was introduced in ECMAScript 2015 (ES6).

**Pros and Cons of Each Approach**

### Spread Operator (`...`)

Pros:

* More concise and readable code
* Can handle nested objects and arrays
* Less prone to errors due to its more explicit syntax

Cons:

* Performance overhead compared to `Object.assign()`
* May not be as widely supported in older browsers or environments

### Object.assign()

Pros:

* Wide support across browsers and environments
* Simple and well-known API
* Can handle nested objects and arrays, although with some limitations

Cons:

* More verbose code
* Less readable for complex merges
* May lead to errors due to its more implicit syntax

**Library Usage**

There is no library being used in this benchmark.

**Special JavaScript Features or Syntax**

The spread operator (`...`) uses a new feature of JavaScript that allows destructuring and spreading objects. This feature was introduced in ECMAScript 2018 (ES2018) and is widely supported across modern browsers and environments.

**Other Alternatives**

If the spread operator or `Object.assign()` were not available, other alternatives could be:

* Using the dot notation (`obj1.prop = obj2.prop`)
* Using a library like Lodash's `merge()` function
* Manually concatenating arrays using `Array.prototype.push()`

These alternatives would likely have different performance characteristics and trade-offs compared to the spread operator and `Object.assign()`.

Overall, this benchmark is testing the performance of two modern JavaScript approaches for merging objects, which should provide insight into the efficiency and readability trade-offs of each method.

Related benchmarks:

JavaScript spread operator vs Object.assign performance 2 (version: 0)

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

Created: 4 years ago by: Registered User

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):