Benchmark: getElementById pre-buffered vs direct

HTML Preparation code:

<div id="testElement"></div>

Script Preparation code:

var testEl = document.getElementById('testElement');

Tests:

getElementById buffered
var el = testEl; var className = el.className;
getElementById unbuffered
var el = document.getElementById('testElement'); var className = el.className;

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
getElementById buffered
getElementById unbuffered

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.

**Benchmark Overview**

The provided benchmark, hosted on MeasureThat.net, compares the performance of two approaches when accessing an element by its ID using JavaScript.

**What is tested?**

The benchmark tests two options:

1. **Pre-buffered approach**: In this approach, the element is retrieved and stored in a variable (`testEl`) before accessing its `className` property.
2. **Direct approach**: In this approach, the element's `className` property is accessed directly without storing it in a variable.

**Options compared**

The two approaches are compared to determine which one is faster in terms of execution time.

**Pros and Cons of each approach:**

1. **Pre-buffered approach**:
	* Pros:
		+ Can improve performance by reducing the number of DOM accesses.
		+ Can be beneficial if the element's `className` property needs to be accessed multiple times.
	* Cons:
		+ Requires more memory to store the element in a variable.
		+ May incur additional overhead due to the assignment operation.
2. **Direct approach**:
	* Pros:
		+ Does not require additional memory storage.
		+ Typically has less overhead compared to the pre-buffered approach.
	* Cons:
		+ Requires accessing the `className` property multiple times, which can be slower.

**Library usage**

There is no explicit library mentioned in the provided benchmark definition. However, the use of `document.getElementById()` suggests that the benchmark is running on a web page with an HTML document structure.

**Special JS features or syntax**

The benchmark uses JavaScript's `var` keyword for variable declarations and the `===` operator for equality checks. No special features or syntax are mentioned.

**Benchmark preparation code**

The provided script preparation code, "var testEl = document.getElementById('testElement');", creates a reference to an HTML element with the ID "testElement". The benchmark then uses this reference to access the `className` property of the element in both the pre-buffered and direct approaches.

**Latest benchmark result**

The latest benchmark result shows that the pre-buffered approach (`getElementById buffered`) outperforms the direct approach (`getElementById unbuffered`) on a Windows desktop with Firefox 108, executing approximately 256.4 million times per second compared to 9.27 million times per second for the direct approach.

**Other alternatives**

For similar benchmarking purposes, alternative JavaScript microbenchmarks may be found on MeasureThat.net or other online platforms. Some examples include:

* "DOM Access: Element by ID vs. Element by Class"
* "CSS Selectors: Simple vs. Complex"
* "Regular Expressions: Simple vs. Complex"

Keep in mind that the performance differences between these benchmarks may vary depending on the specific use case, browser, and hardware configuration.

Related benchmarks:

getElementById pre-buffered vs direct (version: 0)

Comparing performance of: getElementById buffered vs getElementById unbuffered

Created: 3 years ago by: Guest

Jump to the latest result

getElementById buffered

getElementById unbuffered

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):