Benchmark: JavaScript spread operator vs Object.assign performance with empty object as first key

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

Latest run results:

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

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Let's break down what's being tested in this JavaScript benchmark.

**Benchmark Goal**

The goal of this benchmark is to compare the performance of two ways to merge objects in JavaScript:

1. Using the spread operator (`...`).
2. Using `Object.assign()`.

**Options Compared**

There are only two options being compared: using the spread operator and using `Object.assign()`. Both methods are used to create a new object by merging two existing objects.

**Pros and Cons of Each Approach**

1. **Using the Spread Operator (`...`)**:
	* Pros:
		+ Concise and readable syntax.
		+ Easy to use, even for complex objects.
	* Cons:
		+ May be slower than `Object.assign()` due to the overhead of parsing the spread operator.
2. **Using `Object.assign()`**:
	* Pros:
		+ Fast and efficient, as it uses a native JavaScript function optimized for performance.
	* Cons:
		+ Less readable syntax compared to the spread operator.

**Other Considerations**

* In modern browsers, both approaches should be relatively fast, as they are both optimized for performance. However, there might be some subtle differences in caching or parsing overhead that could affect performance.
* The benchmark only measures the execution time of each approach, without considering other factors like memory allocation or object creation.

**Library Used**

There is no explicit library mentioned in the benchmark definition or test cases. However, it's worth noting that `Object.assign()` is a native JavaScript function, so no external library is needed to use it.

**Special JS Feature/Syntax**

The benchmark uses the spread operator (`...`), which was introduced in ECMAScript 2018 (ES9). The syntax allows for concisely merging objects and arrays.

**Alternative Approaches**

If you're interested in exploring alternative approaches, here are a few options:

1. **Using `Object.create()`**: This method creates a new object by creating an object with the specified prototype.
2. **Using a custom merge function**: You could write your own custom function to merge objects, which might be more efficient than using either of the above methods.

Keep in mind that these alternative approaches might not be as concise or readable as the spread operator or `Object.assign()`, but they can provide more control over the merging process.

Related benchmarks:

JavaScript spread operator vs Object.assign performance with empty object as first key (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>

Fastest: N/A

Slowest: N/A

No previous run results

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