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

HTML Preparation code:

<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

Autogenerated LLM Summary (model llama3.2:3b, generated 26 days ago):

LLMs can make mistakes. Check important info.

I'll break down what's being tested in the provided benchmark.

**Benchmark Definition**

The benchmark compares the performance of six different ways to select the first element from an array of elements:

1. `.first()`
2. `:first` (a pseudo-class selector)
3. `.filter(:first)`
4. `.eq(0)`
5. `$($('.container .inner').get(0))`
6. `$($('.container .inner')[0])`

**Options Compared**

The benchmark compares the performance of these six options:

*   **`.first()`**: Selects the first element from an array using the `first()` method.
*   **`:first`**: Uses a pseudo-class selector to select the first element from an array. This is not a standard CSS selector, but rather a jQuery-specific syntax for selecting the first element of an array.
*   **`.filter(:first)`**: Filters the elements in an array and returns only those that match the `:first` pseudo-class. Since `.filter()` doesn't know about pseudo-classes, it will simply return all elements in the array if there is only one element.
*   **`.eq(0)`**: Selects the element at index 0 from an array using the `eq()` method.
*   **$($('.container .inner').get(0))** and $($('.container .inner')[0])**: These two options use jQuery to select the first element from an array. The difference lies in how they access the elements. `$$('.container .inner').get(0)` uses `get()` to retrieve the index of the first element, while `$($('.container .inner')[0])` uses bracket notation (`[0]`) to directly access the first element.

**Pros and Cons**

Here are some pros and cons for each option:

*   **`.first()`**: Pros: Simple, straightforward. Cons: Can be slower if there are many elements in the array.
*   `:first`**: Pros: Compact syntax. Cons: Only works with jQuery, not standard CSS selectors, and can be slower due to the pseudo-class selector.
*   `.filter(:first)`**: Pros: Flexible filtering options. Cons: Slower than the other methods, especially for large arrays, since it needs to filter all elements.
*   `.eq(0)`**: Pros: Fast access to specific elements. Cons: Requires knowing the index of the element, which can be slower if you don't know the index beforehand.
*   `$($('.container .inner').get(0))` and $($('.container .inner')[0])$: Pros: Simple, straightforward syntax for accessing elements by index or using bracket notation. Cons: May be slower than other methods due to the use of `get()` or direct access.

**Library Used**

The `jQuery` library is used throughout this benchmark. jQuery provides a convenient and flexible way to manipulate HTML documents and select elements in DOMs.

**Special JS Feature/Syntax**

None of the options in this benchmark rely on any special JavaScript features or syntax that's not standard.

**Alternatives**

Some alternative ways to select the first element from an array include:

*   Using `slice(0, 1)` to get the first element from an array.
*   Using `indexOf()` and then accessing the element at that index.
*   Using a regular expression to match the first element in an array.

However, these alternatives may not be as straightforward or efficient as the methods tested in this benchmark.

Latest run results:

Run details: (Test run date: 6 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:59.0) Gecko/20100101 Firefox/59.0

Browser/OS: Firefox 59 on Windows

View result in a separate tab

Test name	Executions per second
.first()	29797.2 Ops/sec
:first	20420.8 Ops/sec
.filter(:first)	21257.8 Ops/sec
.eq(0)	9525.7 Ops/sec
$(.get(0))	32723.3 Ops/sec
$([0])	32753.0 Ops/sec

Related benchmarks:

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

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

Created: 7 years ago by: Registered User

Jump to the latest result

.first()

:first

.filter(:first)

.eq(0)

$(.get(0))

$([0])

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 26 days ago):