Benchmark: jQuery event On Performance with event set on each item

HTML Preparation code:

<script src="//ajax.googleapis.com/ajax/libs/jquery/2.2.4/jquery.min.js"></script>

<style>
  #container { visibility: hidden; }
</style>

<div id="container">
</div>

Script Preparation code:

var container = $('#container')
var itemCount = 500;

for (var i = 0; i < itemCount; i++) {
  container.append('<div>Item ' + i + '</div>');
}

var items = container.children();

Tests:

.each loop and single on-assignement
items.each(function(index,item) { var $item = $(item); $item.on('click', function() { console.log('Item clicked'); }); });
no loop and .on-assignement on list
items.on('click', function() { console.log('Item clicked'); });
assign event for each item
items.click(function() { console.log('Item clicked'); });

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
.each loop and single on-assignement
no loop and .on-assignement on list
assign event for each item

Fastest: N/A

Slowest: N/A

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

LLMs can make mistakes. Check important info.

Let's break down the provided JSON data to understand what is being tested.

**Benchmark Definition**

The benchmark measures the performance of adding an event listener to each item in a list using jQuery. The script preparation code creates a container element and appends 500 HTML elements to it, which will serve as the items in the list. The HTML preparation code includes the necessary jQuery library.

**Options Compared**

Three different approaches are compared:

1. **.each loop with single assignment**: This approach uses the `.each` method to iterate over the list of elements and assigns an event listener to each item using the `$item.on()` method.
2. **No loop with .on-assignment on list**: This approach uses the `on()` method directly on the list of elements, assigning the event listener to each item in a single operation.
3. **Assign event for each item**: This approach uses the `$item.click()` method to assign an event listener to each individual element.

**Pros and Cons**

* **.each loop with single assignment**:
	+ Pros: Easy to read and maintain, allows for cancellation of event listeners.
	+ Cons: May be slower due to the iteration overhead.
* **No loop with .on-assignment on list**:
	+ Pros: Faster execution since it avoids iteration overhead.
	+ Cons: Less readable and maintainable, may not support cancellation of event listeners.
* **Assign event for each item**:
	+ Pros: Can be faster for large lists due to the optimized implementation by jQuery.
	+ Cons: May be less readable and maintainable, does not support cancellation of event listeners.

**Library**

The library being used is jQuery, a popular JavaScript library for DOM manipulation and event handling. The `$(item)` syntax is used to select elements from the DOM, and the `$item` variable represents each individual element in the list.

**Special JS Feature or Syntax**

None of the provided benchmark definitions use any special JavaScript features or syntax. They only utilize standard jQuery methods and syntax.

**Alternatives**

If you're interested in exploring alternative approaches or optimizing these benchmarks further, here are some suggestions:

* Consider using a different event handling library, such as vanilla JavaScript's `addEventListener` method.
* Look into caching event listeners to avoid creating new ones for each iteration.
* Investigate the impact of using `$(item)` vs. `item` on performance and readability.

Keep in mind that these alternatives may affect the benchmark results or change the comparison between the three approaches.

Latest run results:

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

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/70.0.3538.67 Safari/537.36

Browser/OS: Chrome 70 on Windows

View result in a separate tab

Test name	Executions per second
.each loop and single on-assignement	1142.2 Ops/sec
no loop and .on-assignement on list	1964.0 Ops/sec
assign event for each item	1817.8 Ops/sec

Related benchmarks:

jQuery event On Performance with event set on each item (version: 0)

Comparing performance of: .each loop and single on-assignement vs no loop and .on-assignement on list vs assign event for each item

Created: 6 years ago by: Guest

Jump to the latest result

.each loop and single on-assignement

no loop and .on-assignement on list

assign event for each item

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):