Benchmark: add and slice vs destructure into

HTML Preparation code:

<!--your preparation HTML code goes here-->

Script Preparation code:

var list = [];
for (var i = 0; i < 1000 * 1000; i++) {
  list.push(i);
}

var newnum = 987654321

const addnewslice = () => {
	list.push(newnum)
    return list.slice(0)
}
const addnewdestructure = () => {return [newnum, ...list]}

Tests:

slice
addnewslice()
destructure
addnewdestructure()

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
slice
destructure

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/134.0.0.0 Safari/537.36

Browser/OS: Chrome 134 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
slice	4040.4 Ops/sec
destructure	77.3 Ops/sec

Autogenerated LLM Summary (model gpt-4o-mini, generated one year ago):

LLMs can make mistakes. Check important info.

The benchmark "add and slice vs destructure into" compares two different approaches for adding an element to an array and then returning a new array: using the `slice` method and using destructuring syntax.

### Tested Approaches:

1. **Slice Method (`addnewslice`)**:
   - **Description**: This approach adds a new number (`newnum`) to an existing list and then returns a shallow copy of that list using the `slice` method. The `slice(0)` call creates a new array that is a copy of the complete list.
   - **Performance Observation**:
     - The execution rate reported is **4040.44 executions per second.**
   - **Pros/Cons**:
     - **Pros**: Simple to understand; widely used; benefits from the optimized internal JavaScript implementation of `slice`.
     - **Cons**: Copies the entire array, which can be less efficient in terms of memory and time for larger arrays due to the additional overhead of creating a copy.

2. **Destructuring Syntax (`addnewdestructure`)**:
   - **Description**: This approach uses the spread operator (`...`) to create a new array containing the new number followed by existing elements in the array. This is a syntactical feature of JavaScript known as destructuring (or spread syntax) that allows elements from one array to be inserted into another.
   - **Performance Observation**:
     - The execution rate reported is **77.28 executions per second.**
   - **Pros/Cons**:
     - **Pros**: More concise and expressive syntax; can be more readable; allows for flexible placements and combinations of values.
     - **Cons**: The performance is significantly lower compared to the slice method; the spread operator tends to be slower due to additional handling required for creating the new array.

### Overview of Results:
- The benchmark clearly shows that the `slice` method outperforms the destructuring approach in terms of execution speed. While the spread syntax is a powerful feature for combining arrays, in this particular use case, it does not match the efficiency of traditional array handling methods.

### Other Considerations:
- **Performance Implications**: For operations that manipulate large arrays or are called frequently in high-performance scenarios (like in loops or extensive computational tasks), the choice of method can significantly impact application speed and memory consumption.
  
- **Readability vs. Performance**: The decision between readability and performance is often a trade-off in software development. While destructuring syntax can be cleaner and more expressive, in performance-critical situations, it may be beneficial to use the more traditional, optimized methods like `slice`.

### Alternatives:
- Other alternatives can include using array methods such as `concat()` which can also add elements and return a new array. However, like destructuring, `concat` can be slower than `slice` for large datasets due to the array copying overhead.
  
- If memory is a concern, modifying the original array in place instead of creating copies could be evaluated, depending on use case requirements and whether immutability is important in the context of the application.

This benchmark serves as an excellent reference point on how seemingly simple syntactical choices in JavaScript can lead to significant performance differences and highlights the importance of understanding both performance and code readability.

Related benchmarks:

add and slice vs destructure into (version: 1)

Comparing performance of: slice vs destructure

Created: one year ago by: Guest

Jump to the latest result

slice

destructure

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model gpt-4o-mini, generated one year ago):