Benchmark: for i inside or outside var 3

Script Preparation code:

var newBody = document.createElement("div");


for (let i;  i < 1000; i++) {
	var divAdded = document.createElement("div");
	divAdded.classList.add("ggclass");
	newBody.appendChild(divAdded);
}

Tests:

inside var
var case1 = document.getElementsByClassName("ggclass"); for (var i = 0; i < case1.length; i++) { // 반복할 내용 console.log(case1[i]); }
outside var
var case1 = document.getElementsByClassName("ggclass"); var i=0; var case1length=case1.length; for ( i ; i < case1length; i++) { // 반복할 내용 console.log(case1[i]); }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
inside var
outside var

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 29 days ago):

LLMs can make mistakes. Check important info.

I'll break down the provided benchmark definition and test cases to help explain what's being tested.

**Benchmark Definition**

The benchmark is testing two approaches for iterating over an array of elements with the `getElementsByClassName` method. The goal is to compare the performance of these approaches.

In JavaScript, when you call `getElementsByClassName`, it returns a live HTMLCollection object that contains all the elements matching the specified class name. This collection can be iterated using traditional loop syntax (e.g., `for` loop), but it's not an array and doesn't support modern array methods like `forEach`.

**Script Preparation Code**

The script preparation code creates a new HTML element (`div`) and appends 1000 child elements with class "ggclass" to the parent element. This is done using two different approaches:

1. Inside the variable declaration:
```javascript
for (let i;  i < 1000; i++) {
    var divAdded = document.createElement("div");
    divAdded.classList.add("ggclass");
    newBody.appendChild(divAdded);
}
```
2. Outside the variable declaration:
```javascript
var i=0;
var case1length=case1.length;
for ( i ; i < case1length; i++) {
    var divAdded = document.createElement("div");
    divAdded.classList.add("ggclass");
    newBody.appendChild(divAdded);
}
```
Both approaches create the same number of elements, but the first approach uses a `for` loop with an initialization expression (`let i`) that is not assigned a value, whereas the second approach declares `i` outside the loop and assigns it the length of the `case1` array.

**Html Preparation Code**

The html preparation code is empty, which means the benchmark doesn't generate any HTML to be executed.

**Individual Test Cases**

There are two test cases:

1. **Inside var**: This test case uses the first approach from the script preparation code, where `i` is initialized inside the loop.
2. **Outside var**: This test case uses the second approach from the script preparation code, where `i` is declared outside the loop.

**Pros and Cons**

Using a traditional `for` loop with an initialization expression (like in the first approach) has some advantages:

* Simplistic and easy to understand
* Can be more efficient for large arrays because it avoids the overhead of creating a new array object

However, this approach also has some drawbacks:

* The `i` variable is not assigned a value initially, which can lead to unexpected behavior if the loop starts executing before the initial assignment.
* It's less flexible and harder to modify compared to other approaches.

On the other hand, declaring `i` outside the loop (like in the second approach) has some advantages:

* Easier to understand and maintain
* More flexible and easier to modify

However, this approach also has some drawbacks:

* Requires more memory because it declares an additional variable (`case1length`) that holds the length of the array.
* Can be slower for very large arrays due to the overhead of accessing `case1.length` repeatedly.

**Libraries and Special Features**

There is no explicit library mentioned in this benchmark definition. However, some libraries like Lodash or Ramda provide utilities for working with arrays and can simplify certain operations.

No special JavaScript features are used in these benchmarks, as they focus on comparing different iteration approaches using standard array methods.

**Alternatives**

If you're interested in exploring alternative approaches to iterating over arrays, here are a few examples:

* Using `Array.prototype.forEach`:
```javascript
newBody.appendChild(...case1);
```
This method avoids the need for explicit looping and is often more efficient.
* Using a `for...of` loop with an array iterator:
```javascript
for (const elem of case1) {
    newBody.appendChild(elem);
}
```
This approach is similar to traditional `for` loops but provides a more concise way to iterate over arrays.

Keep in mind that the performance benefits of these alternatives will depend on the specific use case and the characteristics of the array being iterated.

Latest run results:

Run details: (Test run date: 10 months ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36

Browser/OS: Chrome 120 on Windows

View result in a separate tab

Test name	Executions per second
inside var	7438942.5 Ops/sec
outside var	7438942.5 Ops/sec

Related benchmarks:

for i inside or outside var 3 (version: 1)

Comparing performance of: inside var vs outside var

Created: 10 months ago by: Registered User

Jump to the latest result

inside var

outside var

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 29 days ago):