Benchmark: compare node id getters

HTML Preparation code:


<div id='example'></div>

Tests:

Window id
window.example
getElementById
document.getElementById("example")

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Window id
getElementById

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 4 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/85.0.4183.121 Safari/537.36

Browser/OS: Chrome 85 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Window id	2981776.8 Ops/sec
getElementById	4625755.5 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks on MeasureThat.net.

The provided benchmark compares two approaches to accessing an HTML element: using `window.example` and using `document.getElementById("example")`.

**What is being tested?**

In this benchmark, we're testing the performance difference between two ways to access an HTML element with the ID "example". The element is defined in the HTML preparation code: `<div id='example'></div>`.

The first approach, `window.example`, relies on a quirk of how the browser's window object works. When you assign an HTML element's ID to a global variable (in this case, `window`) using the `id` attribute's `value` property, the browser allows you to access the element directly as if it were a property of the `window` object.

The second approach, `document.getElementById("example")`, is the more traditional and standard way to retrieve an HTML element by its ID using the `document` object.

**Options being compared:**

1. **Using `window.example`**: This approach takes advantage of the browser's quirk mentioned earlier.
2. **Using `document.getElementById("example")`**: This is the more conventional and widely supported method for accessing an HTML element by its ID.

**Pros and Cons of each approach:**

1. **Using `window.example`**:
	* Pros:
		+ Can be faster due to reduced DOM queries.
		+ Some browsers (like Chrome) may exhibit better performance.
	* Cons:
		+ Not widely supported, as it relies on a quirk.
		+ May not work in older browsers or those with similar window object behavior.
2. **Using `document.getElementById("example")`**:
	* Pros:
		+ Widely supported and compatible across most modern browsers.
		+ More predictable performance and less risk of browser-specific quirks.
	* Cons:
		+ May be slower due to additional DOM queries.

**Library usage:**

None explicitly mentioned in this benchmark. However, the use of `document.getElementById()` implies that we're working within the standard JavaScript Document Object Model (DOM).

**Special JS features or syntax:**

No special JS features or syntax are used in this benchmark. It's a straightforward comparison of two accessing methods.

**Other alternatives:**

If you wanted to test other approaches, you might consider:

1. Using `document.querySelector()` instead of `document.getElementById()`.
2. Comparing performance using different DOM query approaches (e.g., `querySelectorAll()`, `getElementsByTagName()`, etc.).
3. Using CSS selectors instead of IDs.
4. Testing the performance of different rendering engines or browsers.

Keep in mind that these alternative approaches might require more complex benchmark setup and execution, but they could provide valuable insights into specific JavaScript performance topics.

Related benchmarks:

compare node id getters (version: 0)

Comparing performance of: Window id vs getElementById

Created: 4 years ago by: Guest

Jump to the latest result

Window id

getElementById

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):