Benchmark: Copy vs JSON - MeasureThat.net

Script Preparation code:

const test1 = [[2,5],[3,5]];
const test2 = [[1,1],[1,7]];
const test3 = [[3,3],[4,4]];

function copy(obj) {
  const [s,e] = obj;
  return [s[0], s[1], e[0], e[1]];
}

function test(func) {
  func(test1);
  func(test2);
  func(test3);
}

Tests:

Copy
var clone = test((obj) => copy(obj));
JSON
var clone = test((obj) => JSON.parse(JSON.stringify(obj)));

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Copy
JSON

Fastest: N/A

Slowest: N/A

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

LLMs can make mistakes. Check important info.

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

**Benchmark Definition**

The benchmark is defined in two parts: `Script Preparation Code` and `Html Preparation Code`.

In the `Script Preparation Code`, we have three arrays `test1`, `test2`, and `test3`, each representing a 2D array. We also define two functions: `copy(obj)` and an anonymous function that takes an object as input.

The `copy(obj)` function is expected to return a new copy of the input object. However, this function has a flaw - it doesn't actually copy the arrays; it simply extracts and returns individual elements from the input array.

The benchmark uses these two functions in a loop, applying them to each test case (`test1`, `test2`, and `test3`). This will measure the execution time of both `copy` and "JSON" (i.e., using `JSON.parse(JSON.stringify(obj))`) for each test case.

**Comparison Options**

There are two comparison options:

1. **Copy**: The original implementation that returns individual elements from the input array, which is not a proper copy.
2. **JSON**: Using `JSON.parse(JSON.stringify(obj))` to create a deep copy of the input object.

Pros and Cons:

* **Copy**:
	+ Pros: Simple and efficient in terms of execution time (since it only needs to extract individual elements).
	+ Cons: It doesn't actually copy the arrays; it just returns a subset of the original data, which may not be what you expect.
* **JSON**:
	+ Pros: Creates an actual deep copy of the input object using `JSON.parse(JSON.stringify(obj))`, ensuring that any nested structures are properly copied.
	+ Cons: It's slower than the simple `copy` function, since it needs to parse and stringify JSON.

**Library**

The benchmark uses no external libraries beyond what's built into JavaScript (i.e., the `JSON` library).

**Special JS Features or Syntax**

There's a special syntax used in the `copy` function: destructuring assignment (`const [s,e] = obj;`). This is a relatively modern feature introduced in ECMAScript 2015.

Now, let's summarize:

* The benchmark compares two approaches to creating a copy of a 2D array: `copy` (returns individual elements) and "JSON" (using `JSON.parse(JSON.stringify(obj))`).
* Pros and Cons of each approach are discussed.
* There's no external library usage beyond built-in JavaScript features.

As for alternatives, some possible approaches could be:

1. **Using a dedicated copy library**: Instead of relying on the simple `copy` function, using a dedicated library like `lodash` or `array-clone` could provide a more reliable and efficient way to create deep copies.
2. **Implementing a custom copy function with recursion**: Creating a recursive function that properly clones nested structures could be a good alternative to the "JSON" approach.
3. **Using a different data structure**: Depending on the specific requirements, using a different data structure (e.g., `Map` or `Set`) might offer better performance or simplicity for certain use cases.

However, without more context about the specific problem domain and requirements, these alternatives may not be relevant to this particular benchmark.

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/119.0.0.0 Safari/537.36 Edg/119.0.0.0

Browser/OS: Chrome 119 on Windows

View result in a separate tab

Test name	Executions per second
Copy	5216487.0 Ops/sec
JSON	605675.6 Ops/sec

Related benchmarks:

Copy vs JSON (version: 0)

Comparing performance of: Copy vs JSON

Created: one year ago by: Guest

Jump to the latest result

Copy

JSON

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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