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querySelector vs querySelectorAll simple
(version: 0)
Comparing performance of:
querySelector vs querySelectorAll
Created:
3 years ago
by:
Guest
Jump to the latest result
HTML Preparation code:
<div class="test"></div> <div class="test"></div> <div class="test"></div> <div class="test"></div> <div class="test"></div> <div class="test"></div> <div class="test"></div> <div class="test"></div> <div class="test"></div> <div class="test"></div>
Tests:
querySelector
document.querySelector(".test:not(.read)")
querySelectorAll
document.querySelectorAll(".test")
Rendered benchmark preparation results:
Suite status:
<idle, ready to run>
Run tests (2)
Previous results
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Test case name
Result
querySelector
querySelectorAll
Fastest:
N/A
Slowest:
N/A
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Autogenerated LLM Summary
(model
llama3.2:3b
, generated one year ago):
Let's dive into the world of JavaScript microbenchmarks on MeasureThat.net. **Benchmark Overview** The benchmark compares the performance of two methods in JavaScript: `document.querySelector()` and `document.querySelectorAll()`. The test cases are designed to find elements with a specific class, `.test`, that does not have another class, `.read`. **Library Used** In this benchmark, the library being used is jQuery (not explicitly mentioned in the JSON, but implied by the use of `$` notation in some test cases). However, since MeasureThat.net focuses on native JavaScript and doesn't allow external libraries in its tests, we can ignore the jQuery aspect. **Options Compared** The two options being compared are: 1. `document.querySelector()` (also known as `querySelector`) 2. `document.querySelectorAll()` (also known as `querySelectorAll`) **Approaches** **1. `document.querySelector()`** This method is used to select a single element that matches the specified selector. In this case, it's used to find an element with the class `.test` that does not have the class `.read`. Pros: * More efficient for finding a single element * Less overhead compared to `querySelectorAll` Cons: * May return null if no matching element is found * Does not guarantee the existence of the selected element **2. `document.querySelectorAll()`** This method returns an HTMLCollection (or NodeList in modern browsers) containing all elements that match the specified selector. Pros: * Returns a collection of matching elements, even if there's only one * Guarantees the existence of at least one matching element Cons: * More overhead compared to `querySelector` * May return more elements than needed if no optimization is applied (e.g., `.not()` pseudo-class) **Other Considerations** When choosing between these two methods, consider the following: * Use `document.querySelector()` when you're sure that only one element matches the selector. * Use `document.querySelectorAll()` when you need to ensure at least one element exists and are willing to accept more elements if necessary. **Special JS Features or Syntax (None)** There are no special JavaScript features or syntax being used in this benchmark. The focus is on comparing two standard methods of querying the DOM. **Alternatives** If you're interested in exploring other performance comparison benchmarks, MeasureThat.net offers a wide range of tests for various aspects of JavaScript and web development. Some examples include: * Benchmarking different array manipulation techniques (e.g., `map()`, `forEach()`, etc.) * Comparing string manipulation methods (e.g., concatenation vs. template literals) * Evaluating the performance of event listeners and listeners in modern browsers Keep an eye out for these tests, which can help you identify potential performance bottlenecks in your own JavaScript code or optimize your existing codebase.
Related benchmarks:
querySelectorAll vs getElementsByClassName Test
querySelectorAll vs getElementsByClassName Test2
querySelector vs getElementsByClassName on multiple elements
querySelector(nth) vs querySelectorAll
querySelector vs querySelectorAll simple (single element result)
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