Benchmark: func initializer vs inlined init

Script Preparation code:

let A=[document.createElement('div'),document.createElement('a'),document.createElement('p')]
let B=(a,b)=>{
  let d=A[a].cloneNode();
  d.className=b;
  return d;
}
let

Tests:

old style clone initializer
let C=[A[2].cloneNode(),A[0].cloneNode(),A[1].cloneNode(),A[0].cloneNode(),A[0].cloneNode(),A[0].cloneNode(),A[0].cloneNode(),A[0].cloneNode()] C[0].className='a b c' C[1].className='d e f' C[2].className='x y z' C[3].className='a b' C[4].className='c d' C[5].className='c d' C[6].className='c d' C[7].className='c d'
mini-initializer
let D=[B(2,'a b c'),B(0,'d e f'),B(1,'x y z'),B(0,'a b'),B(0,'c d'),B(0,'c d'),B(0,'c d'),B(0,'c d')]
array prealloc
let E=Array(8); E[0x0]=B(2,'a b c'); E[0x1]=B(0,'d e f'); E[0x2]=B(1,'x y z'); E[0x3]=B(0,'a b'); E[0x4]=B(0,'c d'); E[0x5]=B(0,'c d'); E[0x6]=B(0,'c d'); E[0x7]=B(0,'c d');

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
old style clone initializer
mini-initializer
array prealloc

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 5 days ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36

Browser/OS: Chrome 131 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
old style clone initializer	805775.8 Ops/sec
mini-initializer	802369.7 Ops/sec
array prealloc	788558.7 Ops/sec

Autogenerated LLM Summary (model gpt-4o-mini, generated 5 days ago):

LLMs can make mistakes. Check important info.

The benchmark defined in the provided JSON analyzes different approaches to initializing and manipulating DOM elements in JavaScript. Here's a breakdown of the key aspects involved in this benchmark, including the options compared, their pros and cons, and other relevant considerations.

### Benchmark Overview

1. **Options Compared**:
    - **Old Style Clone Initializer**: Direct cloning of existing DOM elements.
    - **Mini-Initializer**: Using a helper function to create cloned elements while setting their class names.
    - **Array Prealloc**: Preallocating an array and filling it with cloned elements using the helper function.

### Individual Test Cases

1. **Old Style Clone Initializer**:
    - **Benchmark Definition**:
        ```javascript
        let C=[A[2].cloneNode(),A[0].cloneNode(),A[1].cloneNode(),A[0].cloneNode(),A[0].cloneNode(),A[0].cloneNode(),A[0].cloneNode(),A[0].cloneNode()]
        C[0].className='a b c'
        C[1].className='d e f'
        C[2].className='x y z'
        C[3].className='a b'
        C[4].className='c d'
        C[5].className='c d'
        C[6].className='c d'
        C[7].className='c d'
        ```
    - **Pros**:
        - Straightforward implementation using direct cloning.
        - May benefit from optimizations by the JavaScript engine for direct cloning.
    - **Cons**:
        - Less reusable, as cloning has to be done on a per-instance basis.
        - As the array grows, it may face performance degradation due to redundancy.

2. **Mini-Initializer**:
    - **Benchmark Definition**:
        ```javascript
        let D=[B(2,'a b c'),B(0,'d e f'),B(1,'x y z'),B(0,'a b'),B(0,'c d'),B(0,'c d'),B(0,'c d'),B(0,'c d')]
        ```
    - **Pros**:
        - Uses a reusable function (`B`), which encapsulates cloning and class assignment, promoting code reusability.
        - Class assignment is handled at the time of initialization, which keeps the code clean.
    - **Cons**:
        - Slight overhead of function invocation might introduce latency.
        - Dependent on the implementation of the helper function for performance.

3. **Array Prealloc**:
    - **Benchmark Definition**:
        ```javascript
        let E=Array(8);
        E[0x0]=B(2,'a b c');
        E[0x1]=B(0,'d e f');
        E[0x2]=B(1,'x y z');
        E[0x3]=B(0,'a b');
        E[0x4]=B(0,'c d');
        E[0x5]=B(0,'c d');
        E[0x6]=B(0,'c d');
        E[0x7]=B(0,'c d');
        ```
    - **Pros**:
        - Preallocates an array, which may lead to better performance by avoiding dynamic resizing during element assignment.
        - Follows the same encapsulation benefits of the mini-initializer.
    - **Cons**:
        - Allocating a fixed size array might be unnecessary if the number of elements is unlikely to be constant, leading to memory overhead.
        - Still dependent on the performance of the `B()` function.

### Library and Functions

- **Library/Functions Used**:
    - The `B` function is defined in the preparation code as a helper to manage the cloning process and class assignment. It utilizes `document.createElement` and `cloneNode`, common methods used for handling DOM in JavaScript.

### Special JavaScript Features

- **`cloneNode()` Method**: This method is employed to create a copy of a node. It can clone nodes either shallowly (without its children) or deeply (including its children), which is crucial when creating new elements in the DOM based on existing ones.
- **Arrow Functions**: The use of arrow functions (`=>`) is a newer JavaScript syntax that provides a concise way to define functions. They also inherit the `this` context from their enclosing scope, which can be advantageous in certain situations.

### Other Considerations

- **Optimizing for Reusability**: Compared to the old style, the mini-initializer and array prealloc approaches promote better code reusability, which is generally preferred in software engineering.
- **Performance Trade-Offs**: While the direct cloning method might be slightly faster in certain contexts due to fewer function calls, the reusability and clarity provided by the functional approaches can lead to more maintainable code in larger applications.
- **Consideration for Large Applications**: In applications with many DOM manipulations, maintaining optimal performance becomes essential. Therefore, choosing an approach that balances performance with code maintainability can significantly affect overall application performance.

In conclusion, when assessing which approach to use, software engineers should consider not only the raw performance metrics from benchmarks but also the long-term maintainability and flexibility that each approach offers.

Related benchmarks:

func initializer vs inlined init (version: 4)

Comparing performance of: old style clone initializer vs mini-initializer vs array prealloc

Created: 5 days ago by: Registered User

Jump to the latest result

old style clone initializer

mini-initializer

array prealloc

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model gpt-4o-mini, generated 5 days ago):