<div class="test" data-attribute="test"></div>
<div class="test" data-attribute="test"></div>
<div class="test" data-attribute="test"></div>
<div class="test" data-attribute="test"></div>
<div class="test" data-attribute="test"></div>
<div class="test" data-attribute="test"></div>
<div class="test" data-attribute="test"></div>
<div class="test" data-attribute="test"></div>
<div class="test" data-attribute="test"></div>
<div class="test" data-attribute="test"></div>
<div class="test" data-attribute="test"></div>
<div class="test" data-attribute="test"></div>
<div class="test" data-attribute="test"></div>
<div class="test" data-attribute="test"></div>
<div class="test" data-attribute="test"></div>
<div class="test" data-attribute="test"></div>
<div class="test" data-attribute="test"></div>
<div class="test" data-attribute="test"></div>
<div class="test" data-attribute="test"></div>
<div class="test" data-attribute="test"></div>
<div class="test" data-attribute="test"></div>
<div class="test" data-attribute="test"></div>
<div class="test" data-attribute="test"></div>
<div class="test" data-attribute="test"></div>
var test = document.querySelectorAll('[data-attribute]');
var test = document.querySelectorAll('.test');
--enable-precise-memory-info
flag.
Test case name | Result |
---|---|
data attribute | |
class name |
Test name | Executions per second |
---|---|
data attribute | 440696.6 Ops/sec |
class name | 786494.2 Ops/sec |
Let's break down the provided benchmark and explain what is tested, compared, and their pros and cons.
Benchmark Overview
The benchmark measures the performance of two approaches to selecting elements in an HTML document:
data-attribute
test)class name
test)Data Attribute Test (Test Case 1)
In this test, the script uses document.querySelectorAll('[data-attribute]')
to select all elements with a data-attribute
attribute. However, the data-attribute
attribute is not used as a value for the selection; instead, it's used to specify the selector.
The querySelectorAll()
method will match any element that has an attribute matching the specified pattern ([data-attribute]
). This means that all elements with a data-attribute
attribute, regardless of its value, will be matched.
Class Name Test (Test Case 2)
In this test, the script uses document.querySelectorAll('.test')
to select all elements with the class name test
.
Comparison
The two tests are compared in terms of performance. The benchmark measures the number of executions per second for each test using a specific browser configuration.
Pros and Cons
Other Considerations
When choosing between these approaches, consider the following factors:
Library and Special JS Features
There is no explicit library mentioned in the benchmark definition. However, querySelectorAll()
is a native JavaScript method that uses the DOM API to select elements based on various criteria.
Special JS Feature
The provided benchmark does not use any special or experimental JavaScript features. The code adheres to standard ECMAScript syntax and behavior.
Alternatives
Other alternatives for selecting elements in HTML documents include:
querySelector()
: A more specific version of querySelectorAll()
that matches a single element.getElementById()
: Selects an element by its ID attribute.getElementsByClassName()
: Selects all elements with a specified class name.Keep in mind that these alternatives have different use cases and may offer better performance or readability depending on the specific scenario.