Benchmark: JS: append vs appendChild - list of elements 2

HTML Preparation code:

<div id="container"></div>

Script Preparation code:

var container = document.getElementById("container");
var paragraph = document.createElement("p");

Tests:

append
const elArray = new Array(1000).fill(paragraph); container.append(...elArray);
appendChild
for(let i = 0; i < 1000; i++) { container.appendChild(paragraph); }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
append
appendChild

Fastest: N/A

Slowest: N/A

Latest run results:

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and explain what's being tested.

**Benchmark Overview**

The provided benchmark compares the performance of two approaches: `append` and `appendChild`. Both tests create an array of 1000 elements, each containing a paragraph element created using `document.createElement("p")`.

**Test Cases**

There are two test cases:

1. **"append"`**: This test appends all 1000 paragraph elements to the container using the `container.append(...elArray)` method.
2. **"appendChild"`**: This test adds each of the 1000 paragraph elements individually to the container using a `for` loop: `container.appendChild(paragraph);`.

**What's Being Tested**

The benchmark is testing how fast these two approaches are in terms of execution frequency (i.e., how often the DOM update can be applied). The goal is to determine which approach has better performance.

**Pros and Cons of Each Approach**

* **`append`**:
	+ Pros: Faster, as it updates the DOM all at once.
	+ Cons: May cause layout issues if not used correctly (e.g., adding elements too quickly can lead to unexpected behavior).
* **`appendChild`**:
	+ Pros: Less likely to cause layout issues, as individual elements are added one by one.
	+ Cons: Slower, as it updates the DOM 1000 times.

**Library and Special JS Features**

There are no specific libraries or special JavaScript features mentioned in this benchmark. However, using `document.createElement("p")` is an example of creating a new element dynamically.

**Other Alternatives**

If you want to use other approaches, here are some alternatives:

* **Using `insertAdjacentHTML()`**: Instead of appending elements one by one, you could use `insertAdjacentHTML()` to add all the elements at once. This method is similar to `append` but provides more flexibility in terms of where to insert the content.
* **Using `DOMRequestAnimationFrame()`**: If performance optimization is critical, you could consider using `requestAnimationFrame()` to schedule DOM updates outside of the main loop.

Keep in mind that these alternatives might introduce additional overhead or complexity, and their performance impact will depend on your specific use case.

**Additional Considerations**

When working with dynamic content and layout updates, it's essential to consider factors like:

* **DOM fragmentation**: When elements are added or removed from the DOM, it can lead to fragmentation, causing browsers to work harder to reflow and repaint.
* **Browser caching**: Some browsers may cache DOM updates, which could impact performance if not properly handled.

Understanding these considerations will help you make informed decisions about how to optimize your JavaScript code for optimal performance.

Related benchmarks:

JS: append vs appendChild - list of elements 2 (version: 0)

Comparing performance of: append vs appendChild

Created: 3 years ago by: Guest

Jump to the latest result

append

appendChild

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

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