Benchmark: For, forEach, for of, Map

Script Preparation code:

var arr = [];
for (let i = 0; i < 100000; i++) {
	arr[i] = i;
}
  
function someFn(i) {
	return i * 3 * 8;
}

Tests:

For
for (var x = 0; x < arr.length; x++) { someFn(arr[x]); }
forEach
arr.forEach(function (item){ someFn(item); })
For of
for(let item of arr) { someFn(item) }
map
arr.map((item) => someFn(item))

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
For
forEach
For of
map

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

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

LLMs can make mistakes. Check important info.

I'll break down the provided benchmark JSON and explain what's being tested, along with the pros and cons of each approach.

**Benchmark Definition**

The benchmark defines a common script preparation code for all test cases:
```javascript
var arr = [];
for (let i = 0; i < 100000; i++) {
    arr[i] = i;
}
function someFn(i) {
    return i * 3 * 8;
}
```
This script creates an array `arr` of length 100,000 and defines a simple function `someFn` that takes an integer `i` as input.

**Individual Test Cases**

There are four test cases:

1. **For**: This test case uses the traditional `for` loop to iterate over the `arr` array and call the `someFn` function for each element.
```javascript
for (let x = 0; x < arr.length; x++) {
    someFn(arr[x]);
}
```
Pros: Simple and straightforward implementation.

Cons: This approach can be slower due to the overhead of the loop variable `x` and the increment operation inside the loop.

2. **ForEach**: This test case uses the `forEach` method to iterate over the `arr` array and call the `someFn` function for each element.
```javascript
arr.forEach(function (item) {
    someFn(item);
});
```
Pros: More concise and expressive than the traditional `for` loop.

Cons: The `forEach` method can be slower due to the overhead of the callback function and the iteration logic.

3. **For of**: This test case uses the `for...of` loop to iterate over the `arr` array and call the `someFn` function for each element.
```javascript
for (let item of arr) {
    someFn(item);
}
```
Pros: More concise and expressive than the traditional `for` loop, with better support for iterable objects.

Cons: This approach can be slower due to the overhead of the loop variable `item` and the iteration logic.

4. **Map**: This test case uses the `map()` method to create a new array that applies the `someFn` function to each element of the original `arr` array.
```javascript
arr.map((item) => someFn(item));
```
Pros: More concise and expressive than the traditional `for` loop, with better support for functional programming.

Cons: This approach can be slower due to the overhead of creating a new array and applying the function to each element.

**Library Usage**

None of the test cases use any external libraries.

**Special JS Features/Syntax**

The test cases do not explicitly use any special JavaScript features or syntax, such as async/await, promises, or modern ES6+ features.

**Other Alternatives**

There are other ways to benchmark similar operations, such as:

* Using `Array.prototype.every()` instead of `forEach`
* Using a `while` loop instead of the traditional `for` loop
* Using a different data structure, such as an array with object values instead of primitive values
* Using a different function or algorithm for computing the result

However, these alternatives may not be representative of real-world use cases and may introduce bias in the benchmark results.

Related benchmarks:

For, forEach, for of, Map (version: 0)

Comparing performance of: For vs forEach vs For of vs map

Created: 3 years ago by: Guest

Jump to the latest result

For

forEach

For of

map

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):