Benchmark: JavaScript spread operator vs Object.assign performance HOlla die waldfee

Tests:

Using the spread operator
const firstObject = { a: 'Hello world', b: 1, c: 'foobar', d: 'batman', e: 'hulk' } const secondObject = { moreData: true } const finalObject = { ...secondObject, ...firstObject, };
Using Object.assign
const firstObject = { a: 'Hello world', b: 1, c: 'foobar', d: 'batman', e: 'hulk' } const secondObject = { moreData: true } const finalObject = Object.assign(secondObject, 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 (Macintosh; Intel Mac OS X 10.15; rv:81.0) Gecko/20100101 Firefox/81.0

Browser/OS: Firefox 81 on Mac OS X 10.15

View result in a separate tab

Test name	Executions per second
Using the spread operator	2430580.5 Ops/sec
Using Object.assign	3600135.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down what's being tested in this JavaScript microbenchmark on MeasureThat.net.

**What is being compared?**

The benchmark is comparing two approaches to merge two objects in JavaScript:

1. **Spread Operator (`...`)**: This approach uses the spread operator (`...`) to create a new object that includes all properties from both `firstObject` and `secondObject`.
2. **Object.assign()**: This approach uses the `Object.assign()` method to merge two objects into one.

**Pros and Cons of each approach:**

* **Spread Operator (`...`)**:
	+ Pros:
		- More concise and expressive code
		- Less error-prone, as it's harder to mess up the property names
	+ Cons:
		- May be slower than `Object.assign()` in some cases (more on this later)
* **Object.assign()**:
	+ Pros:
		- Faster than spread operator for large objects, since it uses a more optimized algorithm under the hood
	+ Cons:
		- More verbose code
		- Easier to mess up property names

**Other considerations:**

* The benchmark is running on Firefox 81 on a Macintosh with Intel processor. This might affect the results, as different browsers and environments can behave differently.
* The `ExecutionsPerSecond` metric provides insight into which approach performs better in terms of execution speed.

**What library is being used?**

None. Both approaches are built-in to JavaScript.

**Special JS feature or syntax:**

The spread operator (`...`) was introduced in ECMAScript 2018 (ES2018), so this benchmark takes advantage of a relatively recent feature.

**Benchmark preparation code explanation:**

The `Script Preparation Code` is empty, which means the benchmark assumes that the script being tested doesn't need any special setup or initialization. The `Html Preparation Code` is also empty, suggesting that the benchmark focuses solely on JavaScript performance and doesn't care about HTML rendering or other non-JavaScript aspects.

**Other alternatives:**

While not explicitly mentioned in the benchmark, alternative methods to merge objects could include:

* Using destructuring assignment (`[a, b] = [firstObject.a, secondObject.a];`)
* Using template literals with object literal syntax (e.g., `const finalObject = { ...secondObject, a: 'Hello world', b: 1 };`)
* Using libraries like Lodash or Ramda for utility functions

Related benchmarks:

JavaScript spread operator vs Object.assign performance HOlla die waldfee (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):