Benchmark: JavaScript spread operator vs Object.assign performance (3)

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.

**Overview of the Benchmark**

The provided benchmark, hosted on MeasureThat.net, compares the performance of two approaches for merging objects in JavaScript: the spread operator (`...`) and `Object.assign()`. The benchmark tests how fast each method can create a new object by copying data from two existing objects.

**Options Compared**

There are only two options compared:

1. **Using the Spread Operator**: This approach uses the spread operator (`...`) to merge two objects into a new object. For example:
```javascript
const firstObject = { sampleData: 'Hello world' };
const secondObject = { moreData: 'foo bar' };
const finalObject = { ...firstObject, ...secondObject };
```
2. **Using `Object.assign()`**: This approach uses the `Object.assign()` method to merge two objects into a new object. For example:
```javascript
const firstObject = { sampleData: 'Hello world' };
const secondObject = { moreData: 'foo bar' };
const finalObject = Object.assign({}, firstObject, secondObject);
```
**Pros and Cons of Each Approach**

**Using the Spread Operator**

Pros:

* Concise and readable syntax
* Creates a shallow copy of objects (i.e., only copies own enumerable properties)

Cons:

* Can be slower than `Object.assign()` for large objects or deep merges
* Not supported in older browsers

**Using `Object.assign()`**

Pros:

* Faster than the spread operator for large objects or deep merges
* Supported in all modern browsers and Node.js versions

Cons:

* More verbose syntax compared to the spread operator
* Creates a shallow copy of objects (i.e., only copies own enumerable properties)

**Other Considerations**

* The benchmark does not consider other object merge methods, such as `Object.keys()`, `reduce()`, or custom functions.
* The test uses JavaScript 2015+ features (e.g., arrow functions, template literals), which may not be supported in older browsers.

**Library Used**

There is no specific library used in this benchmark. The `Object.assign()` method is a built-in JavaScript function, and the spread operator is a feature introduced in ECMAScript 2015.

**Special JS Feature or Syntax**

The benchmark uses the following special JavaScript features:

* Arrow functions (`=>`)
* Template literals (`\r\n`)

These features are widely supported in modern browsers and Node.js versions.

Related benchmarks:

JavaScript spread operator vs Object.assign performance (3) (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):