Benchmark: JavaScript spread operator vs Object.create 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 = Object.create(firstObject) secondObject.moreData = 'foo bar';

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:

Run details: (Test run date: 4 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_4) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/81.0.4044.138 Safari/537.36

Browser/OS: Chrome 81 on Mac OS X 10.15.4

View result in a separate tab

Test name	Executions per second
Using the spread operator	22601550.0 Ops/sec
Using Object.assign	695837.3 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into the explanation.

The provided JSON represents a JavaScript microbenchmark on MeasureThat.net, which compares the performance of two approaches: using the spread operator (`...`) and `Object.create` with `Object.assign`.

**Benchmark Overview**

The benchmark creates three objects: `firstObject`, `secondObject`, and `finalObject`. The goal is to see how quickly these objects can be created and assigned data.

**Approaches Compared**

1. **Using the spread operator**: This approach uses the spread operator (`...`) to create a new object that includes all properties from both `firstObject` and `secondObject`. The syntax looks like this: `{ ...firstObject, ...secondObject }`.
2. **Using Object.create + Object.assign**: This approach creates a new object using `Object.create(firstObject)` and then assigns data to it using `Object.assign(secondObject, { moreData: 'foo bar' })`.

**Pros and Cons of Each Approach**

1. **Using the spread operator**:
	* Pros:
		+ More concise syntax.
		+ Can be easier to read and understand for developers familiar with the spread operator.
	* Cons:
		+ May not perform as well as `Object.create + Object.assign` in older browsers or those without native support for the spread operator.
2. **Using Object.create + Object.assign**:
	* Pros:
		+ Widely supported across older browsers and versions of JavaScript.
		+ Can provide more control over object creation and assignment.
	* Cons:
		+ More verbose syntax, which may make it harder to read and understand for developers unfamiliar with `Object.create` and `Object.assign`.

**Library and Special JS Feature**

In this benchmark, the `...` spread operator is used. The `...` symbol was introduced in ECMAScript 2015 (ES6) as a new way to create objects from iterables.

**Other Alternatives**

If you wanted to test alternative approaches, some examples could be:

* Using `Object.assign()` alone: `{ ...firstObject }` would assign the spread operator's result directly to an existing object.
* Using a library like Lodash or Underscore.js, which provide utility functions for working with objects and spreads.

Keep in mind that these alternatives might not be as concise or readable as using the spread operator, but they could still provide interesting performance comparisons.

Related benchmarks:

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

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

Created: 4 years ago by: Guest

Jump to the latest result

Using the spread operator

Using Object.assign

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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