Benchmark: JavaScript spread operator vs Object.assign performance with 3 objects to merge fork

Tests:

Using the spread operator
const firstObject = { sampleData: 'Hello world' } const secondObject = { moreData: 'foo bar' } const thirdObject = { evenMoreData: 'lorim ipsum' } const finalObject = { ...firstObject, ...secondObject, ...thirdObject };
Using Object.assign
const firstObject = { sampleData: 'Hello world' } const secondObject = { moreData: 'foo bar' } const thirdObject = { evenMoreData: 'lorim ipsum' } const finalObject = Object.assign(firstObject, secondObject, thirdObject);

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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I'd be happy to explain what's being tested in this benchmark.

**What is being tested?**

The benchmark compares the performance of two ways to merge multiple objects into a single object:

1. **Using the spread operator**: This method uses the `...` syntax to concatenate the properties of multiple objects.
2. **Using Object.assign()**: This method takes an array of objects as arguments and merges them into a new object.

**Options compared**

The benchmark is comparing these two approaches, which are both implemented in JavaScript. The options being compared are:

* **Spread operator (rest/spread syntax)**: `...`
* **Object.assign()**: a built-in JavaScript function for merging objects

**Pros and Cons of each approach**

1. **Spread Operator**
	* Pros:
		+ Concise and expressive syntax
		+ Readable and easy to understand
		+ Works with modern browsers and most JavaScript engines
	* Cons:
		+ May not be supported in older browsers or environments that don't support rest/spread syntax
		+ Can be slower than `Object.assign()` due to the overhead of evaluating the expression
2. **Object.assign()**
	* Pros:
		+ Wide browser and engine support (backwards compatibility)
		+ Generally faster execution speed due to optimized native function
	* Cons:
		+ Less concise syntax compared to spread operator
		+ May be less readable for some developers

**Library/Utility**

There is no explicit library or utility mentioned in the benchmark. The `Object.assign()` method is a built-in JavaScript function.

**Special JS feature/syntax**

There is no special JavaScript feature or syntax used in this benchmark. It's a straightforward comparison of two approaches.

**Other alternatives**

In addition to the spread operator and `Object.assign()`, there are other ways to merge objects, such as:

* Using the `{ ... }` object literal syntax (similar to spread operator, but with curly braces)
* Using the `concat()` method or `Array.prototype.push()` for older browsers that don't support modern object merging methods
* Implementing a custom merging function using loops and conditional statements

It's worth noting that in recent JavaScript engines, `Object.assign()` has become a standard way to merge objects, making it a more reliable choice.

Related benchmarks:

JavaScript spread operator vs Object.assign performance with 3 objects to merge fork (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):