Benchmark: JavaScript spread operator vs spread to params

Tests:

Using the spread operator
function passFn(obj) { console.log(obj); } const firstObject = { id: 10737, developer: 'СТРАНА Девелопмент', residentialComplexName: 'asd', residentialComplexLink: 'asd', city: 'Москва', station: '', address: '', releaseDate: '', }; const secondObject = { sumMin: '', sumMax: '', image: '', roomsCount: '', squareMeters: '', apartSumMin: '', apartSumMax: '', regulationLink: 'asd', presentationDeveloperLink: '', presentationComplexLink: 'asd', }; const finalObject = { ...firstObject, ...secondObject, }; passFn(finalObject);
Using spread to params
function passFn(obj) { console.log(obj); } const firstObject = { id: 10737, developer: 'СТРАНА Девелопмент', residentialComplexName: 'asd', residentialComplexLink: 'asd', city: 'Москва', station: '', address: '', releaseDate: '', }; const secondObject = { sumMin: '', sumMax: '', image: '', roomsCount: '', squareMeters: '', apartSumMin: '', apartSumMax: '', regulationLink: 'asd', presentationDeveloperLink: '', presentationComplexLink: 'asd', }; passFn({ ...firstObject, secondObject });

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Using the spread operator
Using spread to params

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 26 days ago):

LLMs can make mistakes. Check important info.

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

**Benchmark Definition**

The benchmark is testing two approaches to merge two objects:

1. **Using the spread operator (`...`)**: This approach uses the spread syntax to merge two objects into a new object, like `const finalObject = { ...firstObject, ...secondObject };`.
2. **Using spread to params**: This approach passes two objects as separate arguments to a function that merges them, like `passFn({ ...firstObject, secondObject });`.

**Options being compared**

The benchmark is comparing the performance of these two approaches.

**Pros and Cons**

1. **Using the spread operator (`...`)**:
	* Pros: concise, readable, and efficient.
	* Cons: may not be as performant for very large objects due to the overhead of creating a new object.
2. **Using spread to params**:
	* Pros: can be more flexible for certain use cases (e.g., passing objects as separate arguments).
	* Cons: less readable, and may have performance implications due to function call overhead.

**Library and syntax**

None mentioned in the provided benchmark definition. However, it's worth noting that JavaScript is a dynamically-typed language, which means you don't need explicit type definitions or library imports for most operations.

**Special JS feature/syntax**

No specific JavaScript features or syntax are highlighted in this benchmark, but using the spread operator is a relatively modern feature introduced in ECMAScript 2018 (ES2018).

**Other alternatives**

There are other ways to merge objects in JavaScript, such as:

* Using `Object.assign()`: This method takes one or more source objects and merges their properties into a target object.
* Using the `reduce()` method: This method can be used to create a new object by merging two objects.

Example using `Object.assign()`:
```javascript
const finalObject = Object.assign({}, firstObject, secondObject);
```
Example using `reduce()`:
```javascript
const finalObject = Object.values(firstObject).reduce((acc, value, index) => {
  acc[value] = secondObject[index];
  return acc;
}, {});
```
However, these alternatives may not be as concise or readable as the spread operator approach.

**Benchmark result**

The benchmark results show that Chrome 103 is executing the `Using spread to params` test case more frequently than the `Using the spread operator` test case, with approximately 20 times more executions per second. This suggests that using the spread operator may be faster in this particular scenario.

Latest run results:

Run details: (Test run date: 2 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/103.0.0.0 Safari/537.36

Browser/OS: Chrome 103 on Windows

View result in a separate tab

Test name	Executions per second
Using the spread operator	80689.8 Ops/sec
Using spread to params	173701.8 Ops/sec

Related benchmarks:

JavaScript spread operator vs spread to params (version: 0)

Comparing performance of: Using the spread operator vs Using spread to params

Created: 2 years ago by: Guest

Jump to the latest result

Using the spread operator

Using spread to params

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 26 days ago):