Benchmark: Test performance of different ways of get just one particular DOM element

HTML Preparation code:

<div id="testdiv06">
  <div id="unique06" class="unique" name="unique" data-unique="1">test</div>
</div>
<div id="testdiv05">
  <div id="unique05" class="unique" name="unique" data-unique="1">test</div>
</div>
<div id="testdiv04">
  <div id="unique04" class="unique" name="unique" data-unique="1">test</div>
</div>
<div id="testdiv03">
  <div id="unique03" class="unique" name="unique" data-unique="1">test</div>
</div>
<div id="testdiv02">
  <div id="unique02" class="unique" name="unique" data-unique="1">test</div>
</div>
<div id="testdiv01">
  <div id="unique01" class="unique" name="unique" data-unique="1">test</div>
</div>
<div id="testdiv">
  <div id="unique" class="unique" name="unique" data-unique="1">test</div>
</div>

Script Preparation code:

var i, imax;
var doc = document;

Tests:

getElementsByTagName
var formelem = doc.getElementById('testdiv').getElementsByTagName('div')[0].innerHTML;
querySelector
var test = doc.getElementById('testdiv').querySelector('.unique').innerHTML;
getElementsByClassName
var test = doc.getElementById('testdiv').getElementsByClassName('unique')[0].innerHTML;
getElementsByName
var test = doc.getElementsByName('unique')[0].innerHTML;

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
getElementsByTagName
querySelector
getElementsByClassName
getElementsByName

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 6 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/70.0.3538.110 Safari/537.36

Browser/OS: Chrome 70 on Windows

View result in a separate tab

Test name	Executions per second
getElementsByTagName	1193788.9 Ops/sec
querySelector	1406784.0 Ops/sec
getElementsByClassName	1209756.8 Ops/sec
getElementsByName	1387566.6 Ops/sec

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

LLMs can make mistakes. Check important info.

**Benchmark Overview**

The provided benchmark tests the performance of different DOM element retrieval methods in JavaScript: `getElementById`, `getElementsByTagName`, `querySelector`, `getElementsByClassName`, and `getElementsByName`. The test case uses HTML elements with unique IDs, classes, and names to simulate a real-world scenario.

**Options Compared**

1. **`getElementById`**: This method retrieves an element by its ID.
2. **`getElementsByTagName`**: This method retrieves all elements of a specific tag name.
3. **`querySelector`**: This method retrieves the first element that matches a CSS selector.
4. **`getElementsByClassName`**: This method retrieves all elements with a specific class name.
5. **`getElementsByName`**: This method is not a standard JavaScript method, and it's unclear what this option is supposed to do. It may be a typo or a non-standard implementation.

**Pros and Cons of Each Approach**

1. **`getElementById`**:
	* Pros: Fast and efficient for retrieving elements by ID.
	* Cons: May not work if the element doesn't exist, or if the ID is changed.
2. **`getElementsByTagName`**:
	* Pros: Works with any tag name, but can be slower than `getElementById`.
	* Cons: Returns all elements of the specified tag name, which may be unnecessary.
3. **`querySelector`**:
	* Pros: Efficient and flexible for retrieving elements based on CSS selectors.
	* Cons: May not work if the selector is incorrect or returns multiple elements.
4. **`getElementsByClassName`**:
	* Pros: Works with class names, but can be slower than `getElementById`.
	* Cons: Returns all elements with the specified class name, which may be unnecessary.

**Library and Purpose**

In this benchmark, no libraries are explicitly mentioned. However, it's likely that the test case uses the built-in JavaScript DOM API to interact with the HTML elements.

**Special JS Features or Syntax**

There doesn't seem to be any special JavaScript features or syntax used in this benchmark, apart from possibly using non-standard methods like `getElementsByName`.

**Other Alternatives**

Some alternative approaches for retrieving DOM elements include:

1. Using `querySelectorAll` (a combination of `querySelector` and `textContent`) to retrieve all matching elements.
2. Using `Document.querySelector()` or `Document.querySelectorAll()` with a CSS selector to retrieve elements based on class names, IDs, or attributes.
3. Using libraries like jQuery or React's `find()` method to retrieve elements.

It's worth noting that the performance of these alternatives may vary depending on the specific use case and browser implementation.

Related benchmarks:

Test performance of different ways of get just one particular DOM element (version: 0)

getElementById vs getElementsByTagName vs querySelector vs getElementsByClassName vs getElementsByName

Comparing performance of: getElementsByTagName vs querySelector vs getElementsByClassName vs getElementsByName

Created: 6 years ago by: Guest

Jump to the latest result

getElementsByTagName

querySelector

getElementsByClassName

getElementsByName

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):