Benchmark: JavaScript spread operator vs Object.assign performance, non destructive 2

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 = { moreData: 'foo bar' } const finalObject = Object.assign(firstObject, secondObject);

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

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

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Let's dive into the world of JavaScript microbenchmarks on MeasureThat.net.

The provided JSON represents a benchmark test that compares the performance of two approaches: using the spread operator (`...`) to merge objects, and using `Object.assign()` to achieve the same result.

**Options being compared:**

1. **Using the spread operator (`...`)**: This approach uses the syntax `{ ...firstObject, ...secondObject }` to create a new object that combines the properties of `firstObject` and `secondObject`. The spread operator is a shorthand way to clone an object and merge it with another object.
2. **Using `Object.assign()`**: This approach uses the `Object.assign()` method to merge two objects together. It takes multiple arguments, including the source objects to be merged.

**Pros and Cons of each approach:**

1. **Spread Operator (`...`)**:
	* Pros:
		+ More concise and expressive syntax.
		+ Can create new objects with a different prototype (if needed).
	* Cons:
		+ May not be as efficient as `Object.assign()` for very large objects.
		+ Can lead to unexpected behavior if used incorrectly (e.g., using `...` on a non-object value).
2. **`Object.assign()`**:
	* Pros:
		+ More efficient than the spread operator for large objects.
		+ Ensures that all properties are merged, including inherited ones.
	* Cons:
		+ Less concise syntax compared to the spread operator.
		+ May not be as readable or intuitive for developers familiar with the spread operator.

**Library and purpose:**

None of the provided test cases use any external libraries. However, it's worth noting that `Object.assign()` was introduced in ECMAScript 2015 (ES6) as a part of the standard library.

**Special JavaScript features or syntax:**

The provided benchmark uses a relatively simple and modern approach to merging objects using both the spread operator and `Object.assign()`. There are no complex features or syntax used in this specific benchmark.

**Other alternatives:**

If you need to merge objects with more complex logic, such as filtering out certain properties or applying custom mapping functions, you might consider alternative approaches like:

1. **Lodash's `merge()` function**: A popular utility library that provides a flexible and reusable way to merge objects.
2. **Underscore.js's `_.merge()` function**: Another utility library that offers a similar approach to merging objects.

In summary, the MeasureThat.net benchmark provides a simple yet informative comparison between two approaches for merging objects in JavaScript: using the spread operator and `Object.assign()`. While both methods have their pros and cons, the spread operator is often preferred due to its concise syntax and flexibility.

Related benchmarks:

JavaScript spread operator vs Object.assign performance, non destructive 2 (version: 0)

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

Created: 3 years ago by: Guest

Jump to the latest result

Using the spread operator

Using Object.assign

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):