<body class="hello" data-hello>Hello</div>
document.body.classList.contains('hello')
document.body.dataset.hello;
--enable-precise-memory-info
flag.
Test case name | Result |
---|---|
Class | |
data attribute |
Test name | Executions per second |
---|---|
Class | 2967007.5 Ops/sec |
data attribute | 2582077.5 Ops/sec |
Let's break down the provided benchmark and explain what's being tested.
Benchmark Overview
The benchmark is designed to compare the performance of two approaches: using the classList.contains()
method on an HTML element (referred to as "Class") and accessing a data attribute using the dataset
property (data attribute
). The benchmark uses JavaScript microbenchmarks, which aim to isolate specific parts of code to measure their execution time.
Options Compared
Two options are being compared:
classList.contains()
method to check if an HTML element contains a specific class name.dataset
property, specifically data-hello
.Pros and Cons
Here's a brief analysis of each approach:
dataset
.dataset
property, although most recent versions do.Library/Features Used
The benchmark uses JavaScript features that are widely supported:
classList.contains()
: A built-in method of HTML elements to check for class names.dataset
: A property of HTML elements that provides access to their attributes as key-value pairs.Special JS Feature/Syntax
There's no special JavaScript feature or syntax used in this benchmark. The code is straightforward and uses standard DOM interactions.
Other Alternatives
If you wanted to optimize the performance further, you could consider:
getComputedStyle()
method to retrieve the computed style of an element instead of using classList.contains()
.document.body.hello
) for even faster access.querySelectorAll()
or getElementById()
if you need more complex DOM queries.Keep in mind that the performance differences between these approaches can be minor and may not significantly impact your application's overall performance. The benchmark aims to provide a general idea of how different methods compare, allowing developers to make informed decisions about their code optimization strategies.