Benchmark: spreading vs json parse

Script Preparation code:

var alan = []

for (let i = 0; i < 30; i++) {
    alan.push(Array.from({
            length: 30
        }, (_, index) => index + 1))
    }

Tests:

Spread
let beta = [] beta.push(...alan.slice(0, 2)) beta.push(alan[2].map((_, index) => index === 1 ? 9 : _)) beta.push(...alan.slice(3))
JSON Parse & Stringify
let beta = JSON.parse(JSON.stringify(alan)) beta[2][1] = 9

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Spread
JSON Parse & Stringify

Fastest: N/A

Slowest: N/A

Latest run results:

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and explain what's being tested.

**Benchmark Overview**

The benchmark compares two approaches for creating an array of arrays in JavaScript:

1. Using the spread operator (`...`) to create a new array from an existing one (Spread).
2. Using `JSON.parse(JSON.stringify())` to clone an object, which includes arrays (JSON Parse & Stringify).

**Options Compared**

Two options are being compared:

* **Spread**: This approach uses the spread operator (`...`) to create a new array from `alan.slice(0, 2)` and then pushes elements onto it. The resulting array is created by spreading `alan[2]` into a new array.
* **JSON Parse & Stringify**: This approach uses `JSON.parse(JSON.stringify(alan))` to clone the original `alan` array.

**Pros and Cons of Each Approach**

1. **Spread**:
	* Pros: Efficient, concise, and easy to read.
	* Cons: May not work as expected when dealing with complex objects or arrays.
2. **JSON Parse & Stringify**:
	* Pros: Works for any object, including nested arrays. However, it can be slower due to the overhead of parsing and stringifying the data.
	* Cons: Can lead to memory issues if the cloned array is not properly cleared.

**Library Used**

In this benchmark, `Array.from()` is used to create an array with a specified length and fill it with values from 1 to 30. This function is part of the ECMAScript standard and does not require any external libraries.

**Special JS Feature or Syntax**

None are explicitly mentioned in the provided code.

**Other Considerations**

When dealing with complex data structures, other approaches like using `Array.prototype.slice()` or `Array.prototype.map()` may be more suitable. Additionally, the use of `JSON.parse(JSON.stringify())` can lead to issues if the original object contains functions or other non-serializable values.

**Alternative Approaches**

Other alternatives for creating an array of arrays include:

* Using `Array.from()` with a generator function: `(function* () { yield Array(30).fill().map(() => Math.floor(Math.random() * 100)); }()).join(',')`
* Using a loop and `push` method: `var alan = []; for (let i = 0; i < 30; i++) { alan.push([]); }`

These alternatives may have different performance characteristics or readability implications, but they are not directly compared in the provided benchmark.

Related benchmarks:

spreading vs json parse (version: 0)

Benchmarks spread vs JSON.parse(JSON.stringify())

Comparing performance of: Spread vs JSON Parse & Stringify

Created: 2 years ago by: Guest

Jump to the latest result

Spread

JSON Parse & Stringify

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):