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queryall vs classname
(version: 0)
Comparing performance of:
queryAll vs classname
Created:
2 years ago
by:
Guest
Go to the latest result
HTML Preparation code:
<div class="test" id="test"></div> <div class="test" id="test"></div> <div class="test" id="test"></div> <div class="test" id="test"></div> <div class="test" id="test"></div> <div class="test" id="test"></div> <div class="test" id="test"></div> <div class="test" id="test"></div> <div class="test" id="test"></div> <div class="test" id="test"></div> <div class="test" id="test"></div> <div class="test" id="test"></div> <div class="test" id="test"></div>
Tests:
queryAll
let start = performance.now(); let res = document.querySelectorAll('.test'); console.log(start - performance.now());
classname
let start = performance.now(); let res = document.getElementsByClassName('.test'); console.log(start - performance.now());
Rendered benchmark preparation results:
Suite status:
<idle, ready to run>
Run tests (2)
Previous results
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Test case name
Result
queryAll
classname
Fastest:
N/A
Slowest:
N/A
Latest run results:
Run details:
(Test run date:
2 years ago
)
User agent:
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/119.0.0.0 Safari/537.36
Browser/OS:
Chrome 119 on Mac OS X 10.15.7
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Embed Benchmark Result
<iframe src="https://measurethat.net/Embed?id=487957" width="100%" height="500px"></iframe>
classname
193K/s
queryAll
170K/s
View exact numbers
Test name
Executions per second
✓
classname
192,813 Ops/sec
queryAll
170,392 Ops/sec
Autogenerated LLM Summary
(model
llama3.2:3b
, generated one year ago):
Let's dive into the world of JavaScript microbenchmarks. **What is being tested?** The provided JSON represents two individual test cases: `queryAll` and `classname`. These tests aim to measure the performance difference between using `document.querySelectorAll()` (CSS selector) versus `document.getElementsByClassName()`, which takes a string argument representing the class name. **Options compared:** 1. **CSS selectors (queryAll)**: * Pros: + Easier to read and maintain, as it uses a CSS-like syntax. + More flexible, allowing for more complex selections. + Can be used with various pseudo-classes and attributes. * Cons: + May have slower performance due to the complexity of parsing CSS selectors. + Can be more resource-intensive, especially for large documents or complex selections. 2. **Class names (classname)**: * Pros: + Typically faster and more lightweight than CSS selector-based methods. + Easier to implement and maintain, as it only requires a simple string comparison. * Cons: + Less flexible and less readable than CSS selectors. + Not as suitable for complex selections or pseudo-classes. **Library usage:** There is no explicit library mentioned in the provided JSON. However, if we assume that `document.querySelectorAll()` and `document.getElementsByClassName()` are part of the DOM API (which they are), we can consider them as built-in JavaScript features. **Special JS feature or syntax:** The tests use a simple expression to measure performance, which is common in benchmarking scripts. The `performance.now()` function returns the current time in milliseconds, allowing us to calculate the execution time of the code. Now, let's summarize the pros and cons of each approach: * CSS selectors (queryAll): + Pros: flexible, easy to read and maintain. + Cons: may be slower, more resource-intensive. * Class names (classname): + Pros: faster, easier to implement and maintain. + Cons: less flexible, less readable. **Other alternatives:** If you need to benchmark other approaches or JavaScript features, here are some alternatives: 1. **Regular expressions**: Instead of CSS selectors, you can use regular expressions to match elements in the DOM. 2. **Template literals**: You can use template literals (e.g., `template literals` instead of string concatenation) to improve code readability and performance. 3. **Async/await**: If you're interested in benchmarking asynchronous code, you can use async/await syntax. Remember that the choice of approach depends on your specific requirements and the nature of your project.
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