Benchmark: id vs setAttribute

Script Preparation code:

var ELEMENT = document.createElement('div');

Tests:

id
ELEMENT.id = 'testID';
setAttribute
ELEMENT.setAttribute('id', 'testID');

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
id
setAttribute

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one month ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:131.0) Gecko/20100101 Firefox/131.0

Browser/OS: Firefox 131 on Mac OS X 10.15

View result in a separate tab

Test name	Executions per second
id	13620684.0 Ops/sec
setAttribute	7329309.0 Ops/sec

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

LLMs can make mistakes. Check important info.

I'd be happy to help explain what's being tested in this benchmark.

**Benchmark Definition and Test Cases**

The provided JSON represents a JavaScript microbenchmark test case, which measures the performance difference between two approaches: assigning an ID to a DOM element using the `id` property versus setting an attribute named "id" on the same element.

There are two individual test cases:

1. **"id"`**: This test case assigns the string `'testID'` to the `id` property of the `ELEMENT` variable.
2. **"setAttribute"`**: This test case sets an attribute named "id" with the value `'testID'` on the same `ELEMENT` variable.

**Options Compared**

The two approaches being compared are:

1. **Direct Property Assignment (`id` property)**: Assigning a value directly to the `id` property of the element.
2. **Attribute-Based Approach (`setAttribute`)**: Setting an attribute named "id" with a specified value on the element using the `setAttribute()` method.

**Pros and Cons**

**Direct Property Assignment (using `id` property)**

Pros:

* More concise and readable code
* Faster access to the ID value, as it's stored in a property directly on the object
* Fewer overheads compared to setting an attribute

Cons:

* Some older browsers might not support the `id` property or have quirks with its usage

**Attribute-Based Approach (using `setAttribute`)**

Pros:

* More flexible and extensible, as attributes can be used for other purposes beyond just storing IDs
* Works in most modern browsers, including those that don't support the `id` property directly on elements
* Can be used to store more complex data structures or metadata

Cons:

* Requires an additional method call (`setAttribute()`), which incurs a slight overhead
* The attribute name and value must be explicitly specified, making the code slightly less concise than direct property assignment

**Other Considerations**

* In modern JavaScript, using `data-*` attributes (e.g., `data-id`) is a common practice for storing custom data on elements. This approach is not directly related to the benchmark but is worth mentioning as an alternative method.
* For some use cases, such as accessibility or ARIA support, assigning IDs through `id` properties might be preferred over attribute-based approaches.

**Library and Special JS Features**

There are no libraries explicitly mentioned in this benchmark, nor any special JavaScript features (e.g., async/await, Promises) that would require additional explanation. The focus is solely on the two core approaches being compared: direct property assignment and attribute-based setting.

**Alternatives**

Other alternatives for storing or retrieving data from elements include:

1. **Using `data-*` attributes**: As mentioned earlier, this approach can be more flexible and extensible than attribute-based setting.
2. **Setting a custom data attribute on the element**: This can be achieved using the `setAttribute()` method with a specific prefix (e.g., `data-`) followed by the desired key-value pair.

If you have any further questions or would like me to elaborate on any of these points, please let me know!

Related benchmarks:

id vs setAttribute (version: 0)

Comparing performance of: id vs setAttribute

Created: 8 years ago by: Guest

Jump to the latest result

id

setAttribute

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):