Benchmark: Create 2D Array - MeasureThat.net

Script Preparation code:

var size = 15;

Tests:

While Loop with declaration
const array = []; array.length = size; let index = array.length; while (index-- > 0) { const temp = []; temp.length = size; array[index] = temp; }
While Loop with Array.from
const array = []; array.length = size; let index = array.length; const temp = []; temp.length = size; while (index-- > 0) array[index] = Array.from(temp);
While Loop with Push and Array.From
const array = []; array.length = size; let index = array.length; const temp = []; temp.length = size; while (index-- > 0) array.push(Array.from(temp));
While Loop with Push
const array = []; array.length = size; let index = size; while (index-- > 0) { const temp = []; temp.length = size; array.push(temp); }
Array.from with map
const array = Array.from(Array(size), () => { const temp = []; temp.length = size; return temp; });

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
While Loop with declaration
While Loop with Array.from
While Loop with Push and Array.From
While Loop with Push
Array.from with map

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 11_1_0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/87.0.4280.88 Safari/537.36

Browser/OS: Chrome 87 on Mac OS X 11.1.0

View result in a separate tab

Test name	Executions per second
While Loop with declaration	303659.9 Ops/sec
While Loop with Array.from	303098.6 Ops/sec
While Loop with Push and Array.From	274984.6 Ops/sec
While Loop with Push	283912.2 Ops/sec
Array.from with map	218462.0 Ops/sec

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

LLMs can make mistakes. Check important info.

The provided JSON represents a benchmark for creating a 2D array in JavaScript using different approaches. Let's break down each test case and compare the options.

**Benchmark Definition**
The benchmark definition describes creating a 2D "square" array filled with arrays of the same length.

**Script Preparation Code**
The script preparation code sets the size of the 2D array to be created: `var size = 15;`.

**Html Preparation Code**
There is no HTML preparation code provided.

**Individual Test Cases**

1. **While Loop with Declaration**
This test case uses a traditional while loop with variable declaration:
```javascript
let index = array.length;
while (index-- > 0) {
  const temp = [];
  temp.length = size;
  array[index] = temp;
}
```
Pros: Simple and straightforward.

Cons: May be slower due to the use of `array[index]`, which can lead to a lot of lookups, and the variable declaration can lead to more memory allocation.

2. **While Loop with Array.from**
This test case uses an array from method to create the inner arrays:
```javascript
let index = array.length;
while (index-- > 0) {
  const temp = [];
  temp.length = size;
  array[index] = Array.from(temp);
}
```
Pros: More concise and expressive than the traditional while loop.

Cons: May be slower due to the use of `Array.from`, which can lead to more memory allocation, and it may not perform as well for large arrays.

3. **While Loop with Push and Array.From**
This test case uses a while loop with push and array from method:
```javascript
let index = size;
while (index-- > 0) {
  const temp = [];
  temp.length = size;
  array.push(Array.from(temp));
}
```
Pros: More concise than the traditional while loop.

Cons: May be slower due to the use of `array.push`, which can lead to more memory allocation, and it may not perform as well for large arrays.

4. **While Loop with Push**
This test case uses a while loop with push:
```javascript
let index = size;
while (index-- > 0) {
  const temp = [];
  temp.length = size;
  array.push(temp);
}
```
Cons: May be slower due to the use of `array.push`, which can lead to more memory allocation, and it may not perform as well for large arrays.

5. **Array.from with map**
This test case uses an array from method with a map:
```javascript
const array = Array.from(Array(size), () => {
  const temp = [];
  temp.length = size;
  return temp;
});
```
Pros: Most concise and expressive, as it uses a single line of code.

Cons: May be slower due to the use of `Array.from` with map, which can lead to more memory allocation, and it may not perform as well for large arrays.

**Library**
In this benchmark, the `Array.from()` method is used in three test cases. The purpose of `Array.from()` is to create a new array by mapping an existing iterable (such as an array or string) to a new array with the specified length.

**Special JS Features**
There are no special JavaScript features mentioned in this benchmark.

**Other Alternatives**

In addition to the five test cases provided, other alternatives for creating a 2D array could include:

* Using `Array.fill()` and `map()`: `array.map((_, i) => Array(size).fill().map(() => []))`
* Using `Array.prototype.reduce()`: `array.reduce((acc, _, i) => ({ ...acc, [i]: Array(size).fill().map(() => []) }), {})`

These alternatives may have different performance characteristics compared to the test cases provided.

Related benchmarks:

Create 2D Array (version: 0)

Create a 2D "square" array that is filled with arrays of the same length.

Comparing performance of: While Loop with declaration vs While Loop with Array.from vs While Loop with Push and Array.From vs While Loop with Push vs Array.from with map

Created: 3 years ago by: Guest

Jump to the latest result

While Loop with declaration

While Loop with Array.from

While Loop with Push and Array.From

While Loop with Push

Array.from with map

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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