Benchmark: className vs. className

HTML Preparation code:

<div id="foo"></div>

Tests:

classList classList
var element = document.getElementById("foo"); var i = 1000; while (i--) { element.classList.add("bar"); element.classList.add("bar"); }
classList
var element = document.getElementById("foo"); var i = 1000; while (i--) { element.classList.add("bar"); }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
classList classList
classList

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):

LLMs can make mistakes. Check important info.

I'll break down the benchmark and explain what's being tested.

**Benchmark Definition**

The provided JSON represents the benchmark definition for `MeasureThat.net`. It consists of two main parts:

1. **Script Preparation Code**: This section is empty, indicating that no specific code needs to be executed before running the benchmarks.
2. **Html Preparation Code**: A simple HTML snippet is provided: `<div id="foo"></div>`. This HTML element will be used as a target for the benchmark.

**Individual Test Cases**

There are two individual test cases:

1. **Test Case 1: `classList classList`**
The benchmark definition includes the line `var i = 1000;` and a while loop that iterates from `i--` to `0`. Inside the loop, two lines of code add classes to an HTML element:
```javascript
element.classList.add("bar");
element.classList.add("bar");
```
This is essentially testing the performance difference between using the `classList` property directly on the element (without accessing a specific class name) and accessing a `classList` attribute on the same element.

2. **Test Case 2: `classList`**
The benchmark definition is similar to Test Case 1, but without the `classList.add("bar")` call for the second time:
```javascript
element.classList.add("bar");
```
This test case only measures the performance of accessing and adding classes to an element using the `classList` property.

**Options Compared**

In both test cases, two options are being compared:

* **Using `classList classList`**: This involves directly accessing a non-existent attribute (`classList`) on the element.
* **Using `classList`**: This involves accessing a valid attribute (`classList`) on the element and then calling its methods (e.g., `add()`).

**Pros and Cons of Each Approach**

* **Using `classList classList`**:
	+ Pros: None obvious, but this approach might be faster due to cache hits or other micro-optimizations.
	+ Cons: This attribute does not exist on the element, so using it is likely to result in an error or unexpected behavior.
* **Using `classList`**:
	+ Pros: This is a valid and widely supported method for accessing class lists on HTML elements. It's also relatively fast.
	+ Cons: The performance difference between these two approaches might be negligible, as modern browsers have optimized their implementations of this property.

**Other Considerations**

In both test cases, the use of `while (i--)` loops creates a microbenchmark that can be used to measure performance differences. This approach is useful for comparing performance under specific conditions.

**Library Usage**

There is no explicit library usage in these benchmark definitions.

**Special JavaScript Features or Syntax**

None are mentioned in this benchmark.

**Alternative Approaches**

Other approaches to benchmarking `classList` could involve:

* Using a different data structure, such as an array or object, to store class names.
* Adding or removing classes dynamically using other methods (e.g., `style` property).
* Measuring performance under different scenarios, such as with multiple elements or under heavy load.

These alternative approaches would require modifications to the benchmark definitions and might provide more comprehensive insights into the performance characteristics of the `classList` property.

Related benchmarks:

className vs. className (version: 0)

Comparing performance of: classList classList vs classList

Created: 6 years ago by: Guest

Jump to the latest result

classList classList

classList

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):