Benchmark: is id VS classList.contains

HTML Preparation code:

<div id="some-id" class="c1 c2 c3 c4"></div>

Script Preparation code:

window.el = document.querySelector('#some-id');

Tests:

classList
for (let i = 0, l = 1000; i <= l; i++) { const isMatch = el.classList.contains('c1'); }
id chekc
for (let i = 0, l = 1000; i <= l; i++) { const isMatch = el.id === 'some-id'; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
classList
id chekc

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.

Let's dive into the world of MeasureThat.net and explore what's being tested in this benchmark.

**Benchmark Overview**

The provided JSON defines two individual test cases, each designed to measure the performance difference between using the `id` property versus the `classList.contains()` method for checking if an element matches a class. The benchmark aims to determine which approach is faster and more efficient for large numbers of elements.

**Script Preparation Code**

Before running the tests, the script preparation code sets up an HTML element with the ID "some-id" and assigns it to a variable named `el`. This element will be used as the subject of our performance test.

**Html Preparation Code**

The corresponding HTML code is embedded in the benchmark definition JSON. It creates a `<div>` element with the specified classes ("c1", "c2", "c3", "c4") and assigns it to the `el` variable.

**Test Cases**

There are two individual test cases:

### 1. `classList`

This test case uses the `classList.contains()` method to check if an element matches a specific class.

```javascript
for (let i = 0, l = 1000; i <= l; i++) {
    const isMatch = el.classList.contains('c1');
}
```

**Library:**

`classList` is a native JavaScript property that provides access to the list of classes applied to an element. It's implemented in the browser and doesn't require any additional libraries.

**Pros:**

* Fast and efficient, as it's a native implementation.
* Can handle large numbers of elements with ease.

**Cons:**

* May not be available in older browsers or those with limited JavaScript capabilities.

### 2. `id check`

This test case uses the `id` property to check if an element matches a specific ID.

```javascript
for (let i = 0, l = 1000; i <= l; i++) {
    const isMatch = el.id === 'some-id';
}
```

**Library:**

In this implementation, it appears that the `el` variable has been set to the result of `document.querySelector('#some-id')`, which suggests that the `id` check is being performed on an element retrieved from the DOM using a CSS selector. The exact library used is not explicitly stated.

**Pros:**

* Can be more efficient than `classList.contains()` in certain scenarios.
* Available in older browsers and those with limited JavaScript capabilities.

**Cons:**

* May not handle large numbers of elements as efficiently as `classList.contains()`.
* Requires a CSS selector to retrieve the element, which can add overhead.

**Special JS feature/Syntax:**

The use of template literals (`\r\n`) in the benchmark definitions is not specific to any particular JavaScript version or syntax. It's simply a formatting convention used by MeasureThat.net for readability purposes.

**Other Alternatives:**

For testing the performance difference between `id` and `classList.contains()`, you could also consider using other approaches, such as:

* Using a library like Lodash, which provides an implementation of `includes()` that can be used to test class matching.
* Utilizing a CSS selector library or framework to retrieve elements and test class matching.
* Implementing your own custom solution using JavaScript and DOM manipulation.

Keep in mind that the choice of approach ultimately depends on your specific requirements, target audience, and performance characteristics.

Related benchmarks:

is id VS classList.contains (version: 0)

Comparing performance of: classList vs id chekc

Created: 5 years ago by: Guest

Jump to the latest result

classList

id chekc

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):