Benchmark: Spread vs JSON stringify

Script Preparation code:

var a = Array(1000).fill().map(() => Math.round(Math.random() * 40));

Tests:

Object spread
console.log(`${[...a]}`)
JSON.stringify
console.log(JSON.stringify(a))

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Object spread
JSON.stringify

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 3 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/93.0.4577.82 Safari/537.36

Browser/OS: Chrome 93 on Windows

View result in a separate tab

Test name	Executions per second
Object spread	26160.9 Ops/sec
JSON.stringify	52738.3 Ops/sec

Autogenerated LLM Summary (model llama3.2:3b, generated 6 months 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 the performance of two approaches to create an array from an existing one: using the `...` spread operator (also known as the "spread syntax") versus `JSON.stringify()`.

**Options Compared**

Two options are compared:

1. **Object Spread (`[...a]`)**: This method uses the spread syntax to create a new array by iterating over the elements of the original array `a`. The `Math.random() * 40` expression is used to generate random numbers for each element in the array.
2. **JSON.stringify()`**: This method converts the original array `a` into a JSON string and then parses it back into an array using the `JSON.parse()` method.

**Pros and Cons**

* **Object Spread (`[...a]`)**:
	+ Pros: lightweight, simple to implement, and flexible.
	+ Cons: may not be suitable for large datasets due to potential memory issues and performance overhead from parsing the JSON string.
* **JSON.stringify()`**:
	+ Pros: widely supported, can handle large datasets, and provides a clear and human-readable representation of the data.
	+ Cons: may incur additional overhead due to parsing and stringification operations, which can impact performance.

**Library Used**

None in this specific benchmark. The `JSON` library is used implicitly by the `JSON.stringify()` method, but it's not explicitly imported or referenced in the benchmark code.

**Special JavaScript Features/Syntax**

The benchmark uses a modern JavaScript feature: spread syntax (`[...a]`). This feature was introduced in ECMAScript 2015 (ES6) and has been widely adopted since then. The `Math.random()` expression is also used, which is a common pattern for generating random numbers in JavaScript.

**Other Alternatives**

If you wanted to compare other approaches, here are a few alternatives:

* Using the `Array.prototype.slice()` method instead of spread syntax.
* Using the `Array.prototype.concat()` method with an empty array as its first argument.
* Implementing a custom loop-based approach to create a new array from the original one.

Keep in mind that each alternative would introduce different pros and cons, depending on the specific use case and performance requirements.

Related benchmarks:

Spread vs JSON stringify (version: 0)

Spread vs JSON stringify

Comparing performance of: Object spread vs JSON.stringify

Created: 4 years ago by: Guest

Jump to the latest result

Object spread

JSON.stringify

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 6 months ago):