Benchmark: slice VS splice: keep the first half of an array

Script Preparation code:

var list = [];
for (var i = 0; i < 1000000; i++) {
  list.push(i);
}

Tests:

slice
list.push('slice'); list = list.slice(0, 500000);
splice
list.push('splice'); list.splice(500000, 500000);

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: 3 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/92.0.4515.159 Safari/537.36

Browser/OS: Chrome 92 on Windows

View result in a separate tab

Test name	Executions per second
slice	253.8 Ops/sec
splice	3674062.2 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks on MeasureThat.net.

**What is being tested?**

The provided JSON represents two benchmark definitions: `slice VS splice: keep the first half of an array` and its individual test cases. The main goal is to compare the performance of two approaches:

1. Using the `slice()` method to extract a subset of an array.
2. Using the `splice()` method to remove elements from an array.

**Options compared**

The benchmark compares two options:

a. **Slice**: The `slice()` method creates a shallow copy of a portion of an array, returning a new array object. It's often used when you need to process a subset of data without modifying the original array.

b. **Splice**: The `splice()` method modifies the array by removing or replacing elements at specified indices. It can be used when you need to modify the original array or add new elements.

**Pros and cons of each approach**

a. **Slice**:
	* Pros:
		+ Creates a shallow copy, ensuring the original array remains unchanged.
		+ Can be faster for small arrays or when working with large datasets.
		+ More predictable behavior.
	* Cons:
		+ Creates an additional object in memory, which can consume more resources for large datasets.

b. **Splice**:
	* Pros:
		+ Modifies the original array, reducing memory usage.
		+ Can be faster for large arrays or when working with frequent modifications.
	* Cons:
		+ Modifies the original array, potentially affecting other parts of the codebase.
		+ Can be slower due to the overhead of modifying the array.

**Other considerations**

When choosing between `slice()` and `splice()`, consider the following:

* If you need to process a subset of data without modifying the original array, use `slice()`.
* If you need to modify the original array or add new elements, use `splice()`.
* For large datasets, `slice()` might be more efficient due to its predictable behavior and reduced memory usage.
* For frequent modifications to an array, `splice()` might be a better choice.

**Library usage**

In this benchmark, no libraries are explicitly mentioned. However, it's essential to note that libraries like Lodash or Ramda can provide optimized implementations of these methods or offer alternative approaches, such as using `forEach()` and keeping track of indices manually.

**Special JS feature or syntax**

The benchmark does not mention any special JavaScript features or syntax, such as async/await, generators, or decorators. It focuses solely on the performance comparison between two basic array methods.

I hope this explanation helps you understand what's being tested in this benchmark!

Related benchmarks:

slice VS splice: keep the first half of an array (version: 0)

1M items list

Comparing performance of: slice vs splice

Created: 3 years ago by: Guest

Jump to the latest result

slice

splice

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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