Benchmark: teste 1a - MeasureThat.net

HTML Preparation code:

<div><div class="teste" id="teste1">asfasdfafd</div></div>

Tests:

getElementsByClassName
document.getElementsByClassName(".teste")
querySelectorAll
document.querySelectorAll('.teste')

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
getElementsByClassName
querySelectorAll

Fastest: N/A

Slowest: N/A

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

LLMs can make mistakes. Check important info.

Let's break down what's being tested in this benchmark.

**Benchmark Overview**

The benchmark is comparing the performance of two DOM querying methods: `getElementsByClassName` and `querySelectorAll`. These methods are used to select elements from an HTML document using CSS selectors.

**Tested Options**

There are only two options being compared:

1. **`getElementsByClassName`**: This method returns a live HTMLCollection object that contains all the elements with the specified class name.
2. **`querySelectorAll`**: This method returns a NodeList object that contains all the elements that match the specified CSS selector.

**Pros and Cons**

Here are some pros and cons of each approach:

* **`getElementsByClassName`**:
	+ Pros: Faster, more efficient, and widely supported by older browsers.
	+ Cons: Can return duplicate elements if the class name is present multiple times in the HTML document.
* **`querySelectorAll`**:
	+ Pros: More flexible and accurate, as it can match complex CSS selectors and returns only matching elements.
	+ Cons: Slower than `getElementsByClassName`, especially for older browsers.

**Library Usage**

There is no library usage mentioned in this benchmark. The DOM querying methods themselves are the focus of the test.

**Special JavaScript Features/Syntax**

The benchmark uses a special syntax called "CSS selectors." CSS selectors are used to select elements from an HTML document based on their attributes, classes, IDs, and other properties. In this case, both `getElementsByClassName` and `querySelectorAll` use CSS selectors to filter the elements.

**Other Considerations**

When choosing between `getElementsByClassName` and `querySelectorAll`, consider the following factors:

* **Browser compatibility**: If you need to support older browsers, `getElementsByClassName` might be a better choice.
* **Element selection complexity**: If you need to select multiple elements based on different conditions, `querySelectorAll` might be more suitable.
* **Performance**: If performance is critical, `getElementsByClassName` might be faster.

**Alternatives**

Other DOM querying methods that can be used instead of `getElementsByClassName` and `querySelectorAll` include:

* **`getElementById`**: Selects an element by its ID attribute.
* **`getElementsByTagName`**: Returns a live HTMLCollection object containing all elements with the specified tag name.
* **`querySelector`**: Similar to `querySelectorAll`, but returns only one matching element.

These alternatives may have different performance characteristics and use cases, so it's essential to evaluate their suitability based on your specific requirements.

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/116.0.0.0 Safari/537.36

Browser/OS: Chrome 116 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
getElementsByClassName	3535309.8 Ops/sec
querySelectorAll	1243873.9 Ops/sec

Related benchmarks:

teste 1a (version: 0)

teste1a

Comparing performance of: getElementsByClassName vs querySelectorAll

Created: one year ago by: Guest

Jump to the latest result

getElementsByClassName

querySelectorAll

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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