Benchmark: test matches vs querySelectorAll

HTML Preparation code:

<div class="foo"></div>

Tests:

matches
var element = document.querySelector(".foo"); var i = 5000; while (i--) { element.matches(".foo"); }
querySelectoAll
var i = 5000; while (i--) { document.querySelectorAll(".foo"); }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
matches
querySelectoAll

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 27 days ago):

LLMs can make mistakes. Check important info.

Let's break down the benchmark and its test cases.

**Benchmark Overview**

The benchmark compares two approaches to select elements in an HTML document using JavaScript: `matches()` and `querySelectorAll()`. The goal is to determine which method is faster.

**Test Cases**

There are two test cases:

1. **`matches`**: This test case uses the `matches()` method to check if a specific element matches a CSS selector (`".foo"`). The test code runs a while loop 5000 times, calling `element.matches(".foo")` in each iteration.
2. **`querySelectorAll`**: This test case uses the `querySelectorAll()` method to select all elements with the class `".foo"`. The test code runs a while loop 5000 times, calling `document.querySelectorAll(".foo")` in each iteration.

**Library and Purpose**

In this benchmark, `document.querySelector()` is used, which is a part of the DOM (Document Object Model) API. It allows you to select elements in an HTML document based on a CSS selector or other attributes. The purpose of `querySelectorAll()` is to return a NodeList containing all elements that match the specified selector.

**JavaScript Feature**

There are no special JavaScript features or syntax mentioned in this benchmark. However, it's worth noting that `matches()` was introduced in ECMAScript 2019 (ES10) as a part of the `String.prototype.matches()` method, which allows you to test if a string matches a regular expression.

**Pros and Cons**

Here are some pros and cons for each approach:

* **`matches()`**:
	+ Pros: More concise and expressive than `querySelectorAll()`, can be used with strings as well as regex patterns.
	+ Cons: May have performance implications due to the overhead of regular expressions.
* **`querySelectorAll()`**:
	+ Pros: Can be faster for large selections, allows for dynamic selection logic.
	+ Cons: Returns a NodeList, which may not provide the same level of expressiveness as `matches()`, can be slower for small selections.

**Alternatives**

If you're interested in exploring alternative approaches to selecting elements in JavaScript, here are some options:

* **`getElementsById()`**: This method allows you to select elements based on their ID attribute.
* **`getElementsByTagName()`**: This method returns a NodeList containing all elements with the specified tag name (e.g., `div`, `p`, etc.).
* **`querySelector` and `querySelectorAll()` alternatives**: There are also alternatives like `getElementsByClassName()`, `getElementById()`, and others, which can be used to select elements based on different attributes or properties.

Keep in mind that the choice of selection method depends on the specific use case and performance requirements.

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Linux; Android 6.0.1; SM-G532M) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/92.0.4515.131 Mobile Safari/537.36

Browser/OS: Chrome Mobile 92 on Android 6.0.1

View result in a separate tab

Test name	Executions per second
matches	240.1 Ops/sec
querySelectoAll	24.8 Ops/sec

Related benchmarks:

test matches vs querySelectorAll (version: 0)

Comparing performance of: matches vs querySelectoAll

Created: one year ago by: Guest

Jump to the latest result

matches

querySelectoAll

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 27 days ago):