Benchmark: jQuery .first() vs :first vs .filter(:first) vs .eq(0) vs $(.get(0)) vs $([0]) [2]

HTML Preparation code:

<script type="text/javascript" src="https://code.jquery.com/jquery-3.6.0.slim.min.js"></script>
<div class="container">
  <div class="inner"></div>
  <div class="inner"></div>
  <div class="inner"></div>
  <div class="inner"></div>
  <div class="inner"></div>
</div>

Tests:

.first()
$('.container .inner').first();
:first
$('.container .inner:first');
.filter(:first)
$('.container .inner').filter(':first');
.eq(0)
$('.container .inner').eq(0);
$(.get(0))
$($('.container .inner').get(0));
$([0])
$($('.container .inner')[0]);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
.first()
:first
.filter(:first)
.eq(0)
$(.get(0))
$([0])

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:148.0) Gecko/20100101 Firefox/148.0

Browser/OS: Firefox 148 on Windows

View result in a separate tab

Test name	Executions per second
.first()	908435.2 Ops/sec
:first	472869.5 Ops/sec
.filter(:first)	573988.3 Ops/sec
.eq(0)	830687.5 Ops/sec
$(.get(0))	907097.6 Ops/sec
$([0])	875741.6 Ops/sec

Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):

LLMs can make mistakes. Check important info.

Let's break down what's being tested in this benchmark.

**Benchmark Definition**

The benchmark compares the performance of different ways to select the first element from an array of elements, specifically `.first()`, `:first`, `.filter(:first)`, `.eq(0)`, `$(.get(0))`, and `$([0])` (which is actually the same as `.first()` in jQuery).

**Options Compared**

1. `.first()`: This method returns the first element of a jQuery collection.
2. `:first`: This is a pseudo-class that selects only the first element of a set of elements.
3. `.filter(:first)`: This method filters a jQuery collection and returns a new collection containing only the elements that match the specified condition (in this case, the first element).
4. `.eq(0)`: This method sets or retrieves the value at the specified index of an array or DOM element.
5. `$(.get(0))` and `$([0])`: These methods are actually shortcuts for `$.first()` in older versions of jQuery.

**Pros and Cons**

1. `.first()`: Pros: concise, easy to read; Cons: may not be as efficient as other methods since it has to iterate over the entire collection.
2. `:first`: Pros: concise, easy to read; Cons: may not be supported in older browsers or versions of jQuery.
3. `.filter(:first)`: Pros: flexible, can filter out multiple conditions; Cons: may be slower than other methods since it has to create a new collection and iterate over the entire set of elements.
4. `.eq(0)`: Pros: efficient, sets or retrieves the value at a specific index; Cons: requires knowing the index of the desired element (which may not always be the first one).
5. `$(.get(0))` and `$([0])`: These methods are essentially shortcuts for `$.first()`, but they might still incur some overhead due to the use of older jQuery versions.

**Library and Purpose**

The library being used is jQuery, which is a popular JavaScript library for DOM manipulation and event handling. In this benchmark, jQuery's filtering and indexing capabilities are being tested.

**Special JS Feature or Syntax**

None of the test cases involve special JavaScript features or syntax that would require specific knowledge to understand.

**Other Considerations**

* The benchmark measures the number of executions per second (ExecutionsPerSecond), which is a good indicator of performance.
* The benchmark runs on Firefox 94, which is a relatively recent version of the browser. Testing on other browsers might reveal different results or insights.
* The benchmark uses a simple HTML structure with multiple elements, which should help to isolate the effects of each test case.

**Alternatives**

Some alternative approaches for selecting the first element from an array of elements include:

1. Using `Array.prototype[0]` (JavaScript built-in)
2. Creating an array and using `[0]` or `index`
3. Using a different library, such as Lodash, which provides its own set of utility functions for working with arrays.

Keep in mind that the performance differences between these approaches might be negligible or dependent on specific use cases and requirements.

Related benchmarks:

jQuery .first() vs :first vs .filter(:first) vs .eq(0) vs $(.get(0)) vs $([0]) [2] (version: 0)

Comparing performance of: .first() vs :first vs .filter(:first) vs .eq(0) vs $(.get(0)) vs $([0])

Created: 4 years ago by: Guest

Jump to the latest result

.first()

:first

.filter(:first)

.eq(0)

$(.get(0))

$([0])

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):