Benchmark: spread - MeasureThat.net

Script Preparation code:

var a = {x: 1, y: 100}

Tests:

explicitly
const b = {x: a.x, y: a.y}
spread
const b = {...a}

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
explicitly
spread

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 27 days ago):

LLMs can make mistakes. Check important info.

I'll break down the benchmark and its options, explaining what's being tested and the pros and cons of each approach.

**Benchmark Overview**

The `spread` benchmark measures how different JavaScript libraries handle spreading an object in two ways:

1. Using the syntax `{...a}` (dot spread)
2. Explicitly assigning properties to another object (`const b = {x: a.x, y: a.y}`)

**Options Compared**

We have two options being compared:

### 1. Dot Spread (`{...a}`)

The dot spread syntax is a modern JavaScript feature introduced in ECMAScript 2018 (ES2018). It allows you to create a new object by copying the properties of an existing object using the spread operator.

Pros:

* Concise and readable
* Efficient, as it avoids creating intermediate objects

Cons:

* Not supported in older browsers or environments that don't support ES2018
* May not work as expected if `a` is a complex object with nested properties

**Library Used: None**

The dot spread syntax is a built-in JavaScript feature and doesn't rely on any external library. However, the benchmark might be testing its performance compared to other libraries or methods.

### 2. Explicit Assignment (`const b = {x: a.x, y: a.y}`)

This approach involves explicitly assigning each property of `a` to the corresponding property in `b`. This method is more verbose but ensures that all properties are copied correctly.

Pros:

* Works across older browsers and environments
* Provides a clear and explicit way of copying object properties

Cons:

* More verbose and less readable than dot spread
* May involve unnecessary operations, such as checking for null or undefined values

**Library Used: None**

Like the dot spread syntax, this approach is also built-in JavaScript and doesn't rely on any external library.

**Other Considerations**

When choosing between these two approaches, consider the specific requirements of your use case. If you need to support older browsers or environments, the explicit assignment method might be a better choice. However, if you're targeting modern browsers and want a concise solution, dot spread is likely the way to go.

**Alternatives**

If you're looking for alternative ways to spread objects in JavaScript, consider using libraries like Lodash (`_.cloneDeep`, `_mapValues`) or Underscore.js (`_.extend`).

For example, using Lodash:

```javascript
const _ = require('lodash');

// Using dot spread
const a = { x: 1, y: 100 };
const b = _.cloneDeep(a);

// Or using explicit assignment
const c = {};
c.x = a.x;
c.y = a.y;
```

Keep in mind that these alternatives might have their own pros and cons, depending on your specific use case.

Latest run results:

Run details: (Test run date: 2025 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:59.0) Gecko/20100101 Firefox/59.0

Browser/OS: Firefox 59 on Windows

View result in a separate tab

Test name	Executions per second
explicitly	72635504.0 Ops/sec
spread	1701817.9 Ops/sec

Related benchmarks:

spread (version: 0)

Comparing performance of: explicitly vs spread

Created: 6 years ago by: Guest

Jump to the latest result

explicitly

spread

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 27 days ago):