Benchmark: JavaScript spread operator vs Object.assign vs mutation performance with condition #4

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);
Using mutation
const firstObject = { sampleData: 'Hello world' } const finalObject = { sampleData: firstObject.sampleData }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Using the spread operator
Using Object.assign
Using mutation

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 2 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/106.0.0.0 YaBrowser/22.11.3.823 Yowser/2.5 Safari/537.36

Browser/OS: Yandex Browser 22 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Using the spread operator	141882640.0 Ops/sec
Using Object.assign	11884886.0 Ops/sec
Using mutation	1021811072.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into the benchmark definition and explain what is being tested.

The test case is comparing three approaches to create a new object with similar data:

1. Using the spread operator (`...`)
2. Using `Object.assign()`
3. Using mutation (directly assigning properties)

**Options compared:**

* Spread operator (`...`): This operator allows you to create a new object by copying all the own enumerable properties from an existing object.
* `Object.assign()`: This method copies all enumerable own properties from one or more source objects to a target object.
* Mutation (directly assigning properties): This approach creates a new object and then assigns each property individually.

**Pros and Cons of each approach:**

1. **Spread operator (`...`)**:
	* Pros:
		+ More concise and readable code
		+ Less memory allocation overhead compared to `Object.assign()`
		+ Supports nested objects out of the box
	* Cons:
		+ Performance can be slower due to the overhead of creating a new object
2. **`Object.assign()`**:
	* Pros:
		+ Faster performance since it uses a single method call and avoids object creation overhead
	* Cons:
		+ Less readable code compared to spread operator
		+ May not support nested objects without additional configuration (e.g., using `Object.keys()` or `for...in`)
3. **Mutation (directly assigning properties)**:
	* Pros: None notable, as this approach is generally considered less efficient and less readable.
	* Cons:
		+ More memory allocation overhead compared to spread operator
		+ Less concise code

**Library/Features:**

There are no explicit libraries used in this benchmark.

**Special JS features or syntax:**

The benchmark uses the spread operator (`...`), which is a relatively new feature introduced in ECMAScript 2018. It allows you to create a new object by copying all the own enumerable properties from an existing object.

**Considerations:**

When choosing between these approaches, consider the trade-offs between readability, performance, and memory allocation. If readability is more important than performance, the spread operator might be a better choice. However, if speed is critical, `Object.assign()` might be a better option. For cases where nested objects are involved, the spread operator provides a convenient way to handle them without additional configuration.

**Alternatives:**

Other approaches that could be used for this benchmark include:

* Using destructuring assignment (`const { sampleData } = firstObject; const finalObject = { sampleData };`)
* Using `JSON.parse()` and `JSON.stringify()`
* Using a library like Lodash (which provides a `cloneDeep` function)

However, these alternatives might not be as straightforward or readable as the spread operator, `Object.assign()`, or mutation.

Related benchmarks:

JavaScript spread operator vs Object.assign vs mutation performance with condition #4 (version: 0)

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

Created: 2 years ago by: Guest

Jump to the latest result

Using the spread operator

Using Object.assign

Using mutation

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):