Benchmark: JS spread operator vs Object.assign performance v3

Tests:

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const firstObject = { sampleData: 'Hello world' } const secondObject = { moreData: 'foo bar' } const finalObject = { ...firstObject, ...secondObject };
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
...
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 break down the provided JSON and benchmark data to understand what is being tested.

**Benchmark Purpose**

The primary goal of this benchmark is to compare the performance of two approaches for merging objects in JavaScript:

1. The spread operator (`...`) method
2. `Object.assign()` method

**Options Compared**

The benchmark tests two different ways of creating a new object by combining two existing objects: `firstObject` and `secondObject`.

* **Spread Operator (Spreading) Method**: This approach uses the `...` operator to create a new object that includes all properties from both input objects. The syntax is `const finalObject = { ...firstObject, ...secondObject };`.
* **Object.assign() Method**: This approach uses the `Object.assign()` method to merge two or more objects into one. The syntax is `const finalObject = Object.assign({}, firstObject, secondObject);`.

**Pros and Cons of Each Approach**

1. **Spread Operator (Spreading) Method**
	* Pros:
		+ Concise and readable syntax.
		+ Can handle nested objects.
		+ No need to specify the keys of the source objects explicitly.
	* Cons:
		+ May be slower than `Object.assign()` due to the overhead of creating a new object with spreaded properties.
2. **Object.assign() Method**
	* Pros:
		+ Efficient and fast, as it uses native code under the hood.
		+ Can handle large objects and nested objects efficiently.
	* Cons:
		+ Requires more lines of code to achieve the same result.

**Library Usage**

In this benchmark, there is no explicit library usage. However, `Object.assign()` is a built-in JavaScript method that comes with the language.

**Special JS Feature or Syntax**

There are no special JavaScript features or syntaxes used in these test cases. They only rely on standard JavaScript and ECMAScript features.

**Alternative Approaches**

Besides the spread operator and `Object.assign()`, other methods for merging objects include:

1. Destructuring assignment: `const finalObject = { ...firstObject, ...secondObject };` (similar to the spread operator)
2. Using `for...in` loop or `forEach()` with `Object.keys()`: More verbose approaches that manually iterate over object properties.
3. Other libraries like Lodash (`_.merge()`) or Ramda (`merge()`): Optional alternatives for more complex merging scenarios.

In conclusion, this benchmark tests the performance of two common methods for merging objects in JavaScript: the spread operator and `Object.assign()`. The results can help developers understand which approach is faster and more suitable for their use cases.

Related benchmarks:

JS spread operator vs Object.assign performance v3 (version: 1)

Comparing performance of: ... vs Object assign

Created: 3 years ago by: Registered User

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...

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):