Benchmark: slice VS splice 1234567

Script Preparation code:

var list = [];
for (var i = 0; i < 1000 * 1000; i++) {
  list.push(i);
}

Tests:

slice
list = list.slice(1000);
splice
list.splice(0, 1000);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
slice
splice

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:127.0) Gecko/20100101 Firefox/127.0

Browser/OS: Firefox 127 on Windows

View result in a separate tab

Test name	Executions per second
slice	19846.7 Ops/sec
splice	39776640.0 Ops/sec

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 JSON and explain what's being tested, compared, and other considerations.

**Benchmark Definition**

The benchmark is designed to compare the performance of two approaches: `Array.prototype.slice()` and `Array.prototype.splice()`. The benchmark definition code defines an array `list` with 1 million elements and then calls either `slice()` or `splice()` on the array.

**Options Compared**

There are only two options being compared:

1. `slice()`: This method creates a shallow copy of the specified range of elements in the original array.
2. `splice()`: This method removes elements from the specified index to the end of the array, returning the removed elements as an array.

**Pros and Cons**

* `slice()` has some advantages:
	+ It's generally faster than `splice()` because it only needs to access the elements in the range, whereas `splice()` needs to shift all the elements after the removal.
	+ It creates a new array object without modifying the original array.
* However, `slice()` also has some disadvantages:
	+ It can be slower for large arrays if the JavaScript engine has to allocate a lot of memory to create the new array object.
* On the other hand, `splice()` has some advantages:
	+ It's generally faster than `slice()` because it only needs to update the indices of the elements after the removal.
	+ However, it can be slower for small arrays or if the JavaScript engine has to allocate a lot of memory to create the new array object.

**Library and Purpose**

In this benchmark, there is no explicit library being used. The `Array.prototype.slice()` and `Array.prototype.splice()` methods are part of the built-in JavaScript API.

**Special JS Feature or Syntax (None)**

There are no special JavaScript features or syntax being tested in this benchmark.

**Other Alternatives**

While not explicitly mentioned, other alternatives for large array manipulation could include:

* Using a custom implementation with a loop to shift elements
* Using a library like Lodash or Ramda that provides optimized array methods
* Using a parallel processing approach to divide the work among multiple threads or processes

The benchmark results show that `splice()` is significantly slower than `slice()` in this particular case, likely due to the overhead of updating the indices of the elements after removal.

Related benchmarks:

slice VS splice 1234567 (version: 0)

Comparing performance of: slice vs splice

Created: one year ago by: Guest

Jump to the latest result

slice

splice

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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