Benchmark: JavaScript spread operator vs Object.assign performance 24

Tests:

Using the spread operator 23
const firstObject = { sampleData: 'Hello world' } const secondObject = { moreData: 'foo bar' } const finalObject = { ...firstObject, ...secondObject }; console.log(finalObject === firstObject);
Using Object.assign 22
const firstObject = { sampleData: 'Hello world' } const secondObject = { moreData: 'foo bar' } const finalObject = Object.assign({}, firstObject, secondObject); console.log(finalObject === firstObject);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Using the spread operator 23
Using Object.assign 22

Fastest: N/A

Slowest: N/A

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

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Let's break down the provided benchmark definition and test cases to understand what is being tested.

**What is being tested:**

The benchmark is comparing the performance of two approaches for merging objects in JavaScript:

1. **Spread operator (`...`)**: This syntax was introduced in ECMAScript 2018 (ES2018) and allows you to spread the properties of an object into another object.
2. **Object.assign()**: This method has been part of the JavaScript API since ES5 (ECMAScript 5).

**Options compared:**

The benchmark is comparing two options:

1. Using the spread operator (`...`)
2. Using `Object.assign()` with the `undefined` value as the first argument.

**Pros and Cons:**

* **Spread operator:**
	+ Pros:
		- More concise and readable syntax.
		- Can be used to merge objects in a more declarative way.
	+ Cons:
		- May be slower than `Object.assign()` due to the additional overhead of parsing the spread syntax.
* **Object.assign():**
	+ Pros:
		- Faster execution speed compared to the spread operator.
		- More widely supported across older browsers and environments.
	+ Cons:
		- Less readable and concise syntax.

**Library usage:**

There is no explicit library usage in these test cases. However, it's worth noting that `Object.assign()` relies on the browser's internal implementation of the method, which may vary between engines (e.g., V8 in Chrome).

**Special JS feature or syntax:**

The spread operator (`...`) is a relatively new feature introduced in ES2018, but it has been widely adopted and supported by most modern browsers. If you're using an older browser that doesn't support this syntax, you'll need to use `Object.assign()` instead.

**Other alternatives:**

If you prefer not to use the spread operator or `Object.assign()`, there are alternative ways to merge objects in JavaScript:

* **Using the `{ ... }` syntax:** This syntax is similar to the spread operator but uses curly braces instead of ellipses. It's not as concise, but it achieves the same result.
* **Using the `JSON.parse()` and `JSON.stringify()` methods:** You can use these methods to merge objects by parsing a JSON string that contains the merged object data.
* **Writing a custom merging function:** You can write a custom function to merge objects using a loop or recursion, depending on your specific requirements.

Keep in mind that these alternatives may have performance implications compared to the spread operator and `Object.assign()` methods.

Related benchmarks:

JavaScript spread operator vs Object.assign performance 24 (version: 0)

Comparing performance of: Using the spread operator 23 vs Using Object.assign 22

Created: 5 years ago by: Guest

Jump to the latest result

Using the spread operator 23

Using Object.assign 22

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

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