Benchmark: JavaScript spread operator vs Object.assign performance for Empty Object

Tests:

Using the spread operator
const firstObject = { sampleData: 'Hello world' } const finalObject = { ...firstObject };
Using Object.assign
const firstObject = { sampleData: 'Hello world' } const finalObject = Object.assign({}, firstObject)

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 (X11; Linux x86_64; rv:81.0) Gecko/20100101 Firefox/81.0

Browser/OS: Firefox 81 on Linux

View result in a separate tab

Test name	Executions per second
Using the spread operator	6237495.0 Ops/sec
Using Object.assign	4961066.0 Ops/sec

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

LLMs can make mistakes. Check important info.

I'll break down the explanation into manageable chunks.

**Benchmark Overview**

The provided benchmark is designed to compare the performance of two approaches: using the JavaScript spread operator (`...`) and `Object.assign()` when creating a new object with existing properties from an existing object.

**Options Compared**

Two options are compared:

1. **Using the spread operator (`...`)**: This approach uses the spread operator to create a new object by spreading the properties of the existing object (`firstObject`) into a new object (`finalObject`).
2. **Using `Object.assign()`**: This approach uses the `Object.assign()` method to create a new object by copying the properties from the existing object (`firstObject`) into a new object (`finalObject`).

**Pros and Cons**

Here are some pros and cons of each approach:

1. **Using the spread operator (`...`)**:
	* Pros:
		+ Concise and expressive syntax.
		+ Can be faster, as it avoids the overhead of function calls.
	* Cons:
		+ May not be supported in older browsers or environments that don't understand the spread operator.
2. **Using `Object.assign()`**:
	* Pros:
		+ Widely supported across modern browsers and environments.
		+ Allows for more fine-grained control over object creation, as you can pass additional parameters to `Object.assign()`.
	* Cons:
		+ May be slower due to the overhead of function calls.

**Other Considerations**

Both approaches have their use cases:

1. **Using the spread operator (`...`)**: This is a modern JavaScript feature that's widely supported in most browsers and environments. It's a good choice when you need to create a new object with existing properties, and readability is more important than performance.
2. **Using `Object.assign()`**: This approach is still widely used and supported, especially in older browsers or environments that don't support the spread operator.

**Library Usage**

None of the test cases use any libraries, so there's no additional functionality to consider.

**Special JS Features/Syntax**

The spread operator (`...`) is a modern JavaScript feature introduced in ES6. It allows you to create a new object by spreading the properties of an existing object into a new object. This feature is widely supported across most browsers and environments.

**Benchmark Preparation Code and Test Cases**

The benchmark preparation code is empty, which means that the test cases only need to define the `Benchmark Definition` and `Test Name`. The `Benchmark Definition` specifies how the two approaches should be compared, while the `Test Name` identifies each individual test case. In this case, we have two test cases: "Using the spread operator" and "Using Object.assign".

**Latest Benchmark Result**

The latest benchmark result shows that the **using the spread operator** approach performed slightly better than the **using Object.assign** approach on a desktop Linux system with Firefox 81.

As for alternative approaches, there are other ways to create new objects in JavaScript, such as using the `Object.create()` method or constructing an object using the `new` keyword. However, these approaches may not be as concise or expressive as the spread operator and `Object.assign()`.

Related benchmarks:

JavaScript spread operator vs Object.assign performance for Empty Object (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 2 months ago):