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My Test2
(version: 0)
Comparing performance of:
ClassName vs QuerySelector
Created:
7 years ago
by:
Guest
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HTML Preparation code:
<div class='test'></div>
Tests:
ClassName
document.getElementsByClassName('test');
QuerySelector
document.querySelector('.test');
Rendered benchmark preparation results:
Suite status:
<idle, ready to run>
Run tests (2)
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Test case name
Result
ClassName
QuerySelector
Fastest:
N/A
Slowest:
N/A
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Autogenerated LLM Summary
(model
gemma2:9b
, generated one year ago):
This benchmark compares two ways to select an HTML element by its class name: **Method 1: `document.getElementsByClassName('test')`** * **Description:** This method returns a live HTMLCollection of all elements with the class "test" on the page. * **Pros:** Can be slightly faster for retrieving multiple elements, as it returns a collection rather than a single element. * **Cons:** Returns an array-like object that may not behave exactly like an array in some situations (e.g., iterating over it with `for...of` loop might not work as expected). **Method 2: `document.querySelector('.test')`** * **Description:** This method returns the first HTML element on the page that matches the CSS selector `.test`. * **Pros:** Returns a single element, which can be easier to work with than an entire collection. It's also generally more performant for selecting individual elements. * **Cons:** Only returns the first matching element; if you need all elements, you'll need to use `document.querySelectorAll('.test')`. **Other Considerations:** * **Specificity of Selector:** If there are multiple classes with "test" in them (e.g., `.test-one`, `.test-two`), both methods will select elements matching those as well. * **Performance Differences:** While generally faster for selecting individual elements, the performance difference between these two methods can be subtle and highly dependent on the specific HTML structure of your page. **Alternatives:** * Use a library like jQuery, which provides more concise syntax for element selection. Let me know if you have any other questions!
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querySelectorAll - vs - getElementsByClassName
querySelectorAll vs getElementsByClassName x2
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querySelectorAll vs getElementsByClassName Test2
JS selector functions
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