Benchmark: clone and splice vs map

Tests:

clone and splice
let a = new Array(1000).fill().map((_,i) => i); let b = [...a]; b.splice(500, 10, ...new Array(10).fill().map((_,i) => i*10));
map
let a = new Array(1000).fill().map((_,i) => i); let b = new Array(10).fill().map((_,i) => i*10) let c = a.map((item, i) => i >= 500 && i < 510 ? b[i - 500] : item)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
clone and splice
map

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 2 months ago)

User agent: Mozilla/5.0 (Linux; Android 10; K) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/145.0.0.0 Mobile Safari/537.36

Browser/OS: Chrome Mobile 145 on Android

View result in a separate tab

Test name	Executions per second
clone and splice	42243.5 Ops/sec
map	17837.7 Ops/sec

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

LLMs can make mistakes. Check important info.

I'd be happy to explain what's being tested in the provided JSON benchmark.

**Benchmark Overview**

The provided benchmark compares two approaches for modifying an array: cloning and splicing vs using the `map()` function with a conditional transformation. The goal is to determine which approach is faster and more efficient.

**Options Compared**

There are two test cases:

1. **Clone and Splice**: This approach creates a new array `b` by cloning the original array `a`, then modifies it by splicing in new elements.
2. **Map**: This approach uses the `map()` function to create a new array `c` that transforms the original array `a`. The transformation is done conditionally, where elements between indices 500 and 509 are replaced with elements from an auxiliary array `b`.

**Pros and Cons of Each Approach**

1. **Clone and Splice**:
	* Pros: Can be more intuitive for certain use cases, as it allows explicit control over the modification process.
	* Cons: Creates a new array and modifies another one, which can lead to higher memory usage and slower performance due to object creation and copying.
2. **Map**:
	* Pros: More concise and expressive way to perform transformations on arrays, as it avoids the need for explicit loops or cloning.
	* Cons: Can be less intuitive for certain use cases, as the transformation logic is applied directly to the array.

**Library/External Functions Used**

In this benchmark, none of the standard JavaScript libraries are explicitly mentioned. However, the `map()` function and its cousin `forEach()` are built-in functions that modify arrays in place.

No external libraries or dependencies are used in these test cases.

**Special JS Features/Syntax**

There's no explicit use of special JavaScript features like async/await, decorators, or modern syntax features (e.g., arrow functions, template literals) in these benchmark definitions.

**Other Alternatives**

For modifying arrays, other approaches exist, such as:

1. Using a `forEach()` loop to iterate over the array and apply transformations.
2. Utilizing the `reduce()` function to accumulate changes to an array.
3. Leveraging the `filter()` and `slice()` functions to create new arrays with filtered or sliced subsets of original data.

These alternatives can provide different performance characteristics depending on the specific use case, but may not be as concise or expressive as using `map()`.

Related benchmarks:

clone and splice vs map (version: 0)

Comparing performance of: clone and splice vs map

Created: 2 years ago by: Guest

Jump to the latest result

clone and splice

map

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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