Benchmark: simple array and map vs forEach vs for by cuteLuna v3

Script Preparation code:

var arr = [{ name: 'luna', id: 3 },{ name: 'abc', id: 4 }, { name: 'eee', id: 3 }]

Tests:

map
const newArr = arr.map(e=> ({ label: e.name, id: e.id}))
foreach
const newArr = []; arr.forEach((item, index) => { newArr[index] = {label: item.name, id: item.id} })
for
const arrLength = arr.length; const newArr = []; for (let i = 0; i < arrLength; i++) { newArr[i] = {label: arr[i].name, id: arr[i].id} }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
map
foreach
for

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36

Browser/OS: Chrome 120 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
map	19556876.0 Ops/sec
foreach	17270668.0 Ops/sec
for	4000572.8 Ops/sec

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

LLMs can make mistakes. Check important info.

I'll break down the provided benchmark definition and test cases for you.

**Overview of the Benchmark**

The benchmark, created by cuteLuna v3, compares three ways to transform an array in JavaScript: `map()`, `forEach()` with a callback function, and a traditional `for` loop. The goal is to measure which approach is the fastest.

**Options Compared**

1. **Map()**: This method creates a new array with the results of applying a provided function on every element in this array.
2. **ForEach() with a callback function**: This method executes a user-supplied function once for each element in an array.
3. **Traditional For Loop**: This method uses a `for` loop to iterate over the elements of the array and creates a new array with the transformed elements.

**Pros and Cons of Each Approach**

1. **Map()**:
	* Pros: concise, efficient, and easy to read.
	* Cons: can be slower than traditional loops for very large arrays due to the creation of an intermediate array, which can lead to memory usage issues in some browsers.
2. **ForEach() with a callback function**:
	* Pros: flexible, works well with large datasets, and can be used with other methods like `Array.prototype.every()` or `Array.prototype.some()`.
	* Cons: can be slower than traditional loops due to the overhead of the callback function execution.
3. **Traditional For Loop**:
	* Pros: control over iteration, no memory allocation for an intermediate array.
	* Cons: verbose, error-prone, and less readable.

**Library Used**

None of the test cases use any external libraries.

**Special JS Feature or Syntax**

The benchmark does not mention any special JavaScript features or syntax. However, it's worth noting that the `map()` method is a modern JavaScript feature introduced in ECMAScript 2012 (ES6).

**Benchmark Preparation Code and Test Cases**

The preparation code for each test case creates an array of objects with `name` and `id` properties:
```javascript
var arr = [{ name: 'luna', id: 3 }, { name: 'abc', id: 4 }, { name: 'eee', id: 3 }];
```
Each test case then performs the transformation using one of the three methods:

1. **Map()**:
```javascript
const newArr = arr.map(e => ({ label: e.name, id: e.id }));
```
2. **ForEach() with a callback function**:
```javascript
arr.forEach((item, index) => {
  newArr[index] = { label: item.name, id: item.id };
});
```
3. **Traditional For Loop**:
```javascript
const arrLength = arr.length;
const newArr = [];
for (let i = 0; i < arrLength; i++) {
  newArr[i] = { label: arr[i].name, id: arr[i].id };
}
```
The benchmark then measures the execution time of each test case using the `ExecutionsPerSecond` metric.

**Alternatives**

Other alternatives for transforming arrays in JavaScript include:

* Using `Array.prototype.reduce()` or `Array.prototype.filter()`.
* Using a library like Lodash, which provides a `map()` method.
* Using a functional programming approach with functions like `curry()` or `partial()`.

Related benchmarks:

simple array and map vs forEach vs for by cuteLuna v3 (version: 0)

Comparing performance of: map vs foreach vs for

Created: one year ago by: Guest

Jump to the latest result

map

foreach

for

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):