Benchmark: swap with splice vs spread

Script Preparation code:

var array = [];
var length = 1000000
for(var i = 0; i < length; i++){array.push(Math.random());}

Tests:

splice
for(let i = 0; i < array.length-1; i++){array.splice(i,2,array[i+1],array[i]);}
spread
for(let i = 0; i < array.length-1; i++){[array[i+1],array[i]]=[array[i],array[i+1]]}

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
splice
spread

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/127.0.0.0 Safari/537.36

Browser/OS: Chrome 127 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
splice	8.8 Ops/sec
spread	8.2 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into the world of MeasureThat.net and explore what's being tested in this benchmark.

**What is being tested?**

The benchmark is testing two different approaches to swapping elements in an array:

1. Using `splice()`
2. Using the spread operator (`...`)

Both approaches are used to swap two elements in the array, but with a twist: the first element is removed and replaced with the second element.

**Options compared**

Here's a summary of the options being compared:

* `splice()`: A built-in JavaScript method that modifies an array by removing or inserting elements at specific indices.
* Spread operator (`...`): A feature introduced in ECMAScript 2018, which allows creating new arrays from existing ones using the syntax `[...array]`.

**Pros and Cons**

### Splice()

Pros:

* Widely supported across different browsers and versions
* Fast and efficient, especially for small to medium-sized arrays

Cons:

* Can be slower than the spread operator for large arrays due to its iterative nature
* May cause performance issues if used excessively, as it requires updating multiple array indices

### Spread Operator (`...`)

Pros:

* Faster and more efficient than `splice()` for large arrays
* Creates a new array object, which can be beneficial for memory management and caching

Cons:

* Less widely supported across older browsers and versions (although still supported in most modern browsers)
* Can cause performance issues if not optimized correctly (e.g., using unnecessary iterations)

**Library usage**

In this benchmark, the `splice()` method is used with an array created using a simple loop. The spread operator (`...`) is used to create a new array and swap elements without modifying the original array.

**Special JavaScript feature**

The spread operator (`...`) is a relatively new feature in JavaScript (introduced in ECMAScript 2018), which allows creating new arrays from existing ones. This benchmark showcases its performance advantages over `splice()` for swapping elements in an array.

**Other considerations**

* Array indexing and bounds checking can impact performance, especially when using `splice()`.
* Using `Array.prototype.slice()` or other methods to create a copy of the array before modifying it can also affect performance.
* MeasureThat.net's benchmarking framework likely optimizes the code for each test case to ensure consistent results.

**Alternatives**

If you're looking for alternative approaches to swapping elements in an array, consider:

1. Using `Array.prototype.slice()` to create a new array and swap elements: `var newArray = array.slice(); newArray[0] = array[1]; newArray[1] = array[0];`
2. Using a library like Lodash or Ramda, which provide optimized functions for array manipulation.
3. Implementing a custom swapping function using bitwise operations, such as XOR.

Keep in mind that each approach has its trade-offs and performance characteristics, and MeasureThat.net's benchmark helps evaluate these factors in different scenarios.

Related benchmarks:

swap with splice vs spread (version: 0)

Comparing performance of: splice vs spread

Created: one year ago by: Guest

Jump to the latest result

splice

spread

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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