Benchmark: getElementById vs getElementsByTagName vs querySelector

HTML Preparation code:

<sy-sd-portal id="test"></sy-sd-portal>

Tests:

getElementById
var test = document.getElementById('test').innerHTML;
getElementsByTagName
var test = document.getElementsByTagName('sy-sd-portal')[0].innerHTML;
querySelector
var test = document.querySelector('sy-sd-portal').innerHTML;

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
getElementById
getElementsByTagName
querySelector

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):

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Let's break down the provided JSON data and explain what's being tested, compared, and their pros and cons.

**Benchmark Definition**
The benchmark compares the performance of three different methods to retrieve an HTML element: `getElementById`, `getElementsByTagName`, and `querySelector`. The goal is to determine which method is the fastest.

**Script Preparation Code**: None is provided in this case.

**Html Preparation Code**: A simple HTML snippet is used, containing a single `<sy-sd-portal>` element with an ID of "test".

**Individual Test Cases**

1. **getElementById**
	* Benchmark Definition: `var test = document.getElementById('test').innerHTML;`
	* This method uses the `id` attribute of the HTML element to identify it.
	* Pros:
		+ Fast and efficient, especially when using a single ID per element.
	+ Widely supported by browsers.
	* Cons:
		+ Limited to elements with unique IDs.
		+ May not work well if multiple elements have the same ID (although this is rare).
2. **getElementsByTagName**
	* Benchmark Definition: `var test = document.getElementsByTagName('sy-sd-portal')[0].innerHTML;`
	* This method uses the `tagName` attribute of the HTML element to identify it.
	* Pros:
		+ Can retrieve multiple elements with the same tag name.
		+ Works even if there are no elements with the specified tag name.
	* Cons:
		+ May be slower than `getElementById` for single-element queries.
		+ Less efficient when searching for a large number of elements.
3. **querySelector**
	* Benchmark Definition: `var test = document.querySelector('sy-sd-portal').innerHTML;`
	* This method uses CSS selectors to identify the HTML element.
	* Pros:
		+ Highly flexible and powerful, allowing complex selections.
		+ Fast and efficient, especially for modern browsers.
	* Cons:
		+ May be slower than `getElementById` or `getElementsByTagName` for simple queries.
		+ Not as widely supported by older browsers.

**Library**
None is explicitly mentioned in the provided data. However, it's likely that the `<sy-sd-portal>` element is a custom HTML tag created for this benchmark purpose.

**Special JS Feature or Syntax**
The use of `querySelector` and CSS selectors is an example of modern JavaScript features. The `getElementsByTagName` method uses the older W3C DOM Level 2 specification.

**Other Alternatives**

1. **getElementsByClassName**: Similar to `getElementsByTagName`, but allows specifying a class name instead of a tag name.
2. **getElementByXPath**: A more complex query language for selecting elements based on their structure and attributes, similar to CSS selectors.
3. **QuerySelectorAll**: Returns an array of all matching elements instead of just the first one.

These alternatives offer different trade-offs between flexibility, performance, and compatibility with older browsers.

Related benchmarks:

getElementById vs getElementsByTagName vs querySelector (version: 0)

Comparing performance of: getElementById vs getElementsByTagName vs querySelector

Comparing performance of: getElementById vs getElementsByTagName vs querySelector

Created: 4 years ago by: Guest

Jump to the latest result

getElementById

getElementsByTagName

querySelector

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):