Benchmark: TestingForMyself

HTML Preparation code:

<div class="test"></div>
<div class="test"></div>
<div class="test"></div>
<div class="test"></div>
<div class="test"></div>

Tests:

declare
let i; let exampleDivs = document.querySelectorAll('.test'); let exampleDivsLength = exampleDivs.length; for (i = 0; i < exampleDivsLength; i++) { console.log(exampleDivs[i]); }
Without declare
let i; let exampleDivs = document.querySelectorAll('.test'); for (i = 0; i < exampleDivs.length; i++) { console.log(exampleDivs[i]); }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
declare
Without declare

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

This benchmark does not have any results yet. Be the first one to run it!

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

LLMs can make mistakes. Check important info.

Let's break down what's being tested in the provided JSON.

**Overview**

The benchmark is comparing two approaches to iterating over an array of HTML elements using `document.querySelectorAll`. The test cases are designed to measure the performance difference between these two approaches: one that declares a variable (`let i`) and another that doesn't declare it (using `exampleDivs.length` directly).

**Options being compared**

1. **Declare a variable (`let i`)**:
	* Pros:
		+ More readable code, as it clearly declares the intention to use the loop.
		+ May lead to better optimization by compilers or JavaScript engines.
	* Cons:
		+ May incur additional overhead due to the declaration and initialization of the variable.
2. **Use `exampleDivs.length` directly**:
	* Pros:
		+ May be faster, as it avoids the overhead of declaring a variable.
	* Cons:
		+ Less readable code, as it's not immediately clear what the intention is.

**Other considerations**

1. **Browser and engine differences**: The benchmark results are reported for Firefox 80 on Windows Desktop. Different browsers and engines may optimize or behave differently when dealing with these two approaches.
2. **Execution frequency**: The test reports the number of executions per second (ExecutionsPerSecond). A higher value indicates better performance.

**Library and its purpose**

None, as this is a simple, bare-metal JavaScript benchmark.

**Special JS feature or syntax**

The benchmark uses `let` and `for...of` loop, which are relatively modern features introduced in ECMAScript 2015 (ES6).

**Benchmark preparation code**

The preparation code generates four HTML elements with the class `test`, which is then queried using `document.querySelectorAll`. The script also declares a variable `exampleDivsLength` to store the length of the query result, but it's not used in the test case.

**Other alternatives**

If you wanted to explore alternative approaches or variations on these benchmarks, here are some ideas:

* Compare the performance of different array iteration methods (e.g., `forEach`, `map`, `reduce`) instead of `for` loops.
* Investigate the impact of using `const` variables versus `let` variables.
* Use a more complex HTML structure or multiple iterations to simulate real-world scenarios.
* Compare the performance of these approaches in different browsers, engines, or on mobile devices.

These alternatives can help you better understand how different code patterns affect performance and whether specific optimizations make a noticeable difference.

Related benchmarks:

TestingForMyself (version: 0)

Comparing performance of: declare vs Without declare

Created: 5 years ago by: Guest

Jump to the latest result

declare

Without declare

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):