Benchmark: Slice vs Splice vs Shift in cycle

Script Preparation code:

var array = [1, 2, 3, 4, 5, 6, 7, 8]
var itemsToRemove = 5

Tests:

array.slice()
for (let i = 0 ; i < itemsToRemove ; i++) array = array.slice(1)
array.splice()
for (let i = 0 ; i < itemsToRemove ; i++) array.splice(0, 1)
array.shift()
for (let i = 0 ; i < itemsToRemove ; i++) array.shift()

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
array.slice()
array.splice()
array.shift()

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/124.0.0.0 Safari/537.36

Browser/OS: Chrome 124 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
array.slice()	1587958.4 Ops/sec
array.splice()	2284566.0 Ops/sec
array.shift()	2556044.5 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 JavaScript microbenchmarks on MeasureThat.net.

**Benchmark Definition**

The benchmark defines three test cases:

1. Removing 2 items from the beginning of an array using `array.slice(1)`.
2. Removing 2 items from the beginning of an array using `array.splice(0, 1)`.
3. Removing 2 items from the beginning of an array using `array.shift()`.

**Options Compared**

The benchmark compares three different approaches to remove 2 items from the beginning of an array:

* **`array.slice(1)`**: Creates a new array by copying all elements except the first two.
* **`array.splice(0, 1)`**: Modifies the original array by removing the first element and shifting the remaining elements one position forward.
* **`array.shift()`**: Removes the first element from the array.

**Pros and Cons of Each Approach**

* `array.slice(1)`: Pros:
	+ Creates a new array without modifying the original, which can be more efficient in terms of memory usage.
	+ Can be faster because it avoids mutating the original array.
	+ Does not require iterating over the entire array.
*   Cons:
	+ Creates a new array and copies all elements, which can be slower than other approaches.
	+ May incur additional memory allocation and copying overhead.
* **`array.splice(0, 1)`**: Pros:
	+ Modifies the original array in place, which can be faster because it avoids creating a new array.
	+ Can take advantage of compiler optimizations that minimize the number of allocations.
*   Cons:
	+ Mutates the original array, which can have unintended consequences if the array is used elsewhere.
	+ May incur additional overhead due to the mutation.
* **`array.shift()`**: Pros:
	+ Removes the first element without creating a new array or modifying the original array in place.
	+ Can be faster because it avoids unnecessary allocations and copies.
*   Cons:
	+ Only removes the first element, which may not meet the requirement of removing 2 items from the beginning.

**Other Considerations**

The benchmark does not take into account other factors that could affect performance, such as:

* Array length: The benchmark only tests with a fixed array length of 8 elements.
* Array initialization: The benchmark initializes the array with values starting from 1 and incrementing by 1.
* Loop optimization: The benchmark uses simple `for` loops to iterate over the removal process.
* Browser and platform differences: While the benchmark runs on Chrome 124, other browsers or platforms might exhibit different performance characteristics.

**Library and Special JS Features**

There are no libraries mentioned in the provided code. However, if you're interested in testing other libraries or special JavaScript features, MeasureThat.net also supports:

* Testing specific libraries like `Lodash` or `Ramda`.
* Testing special JavaScript features like `async/await`, `let const`, or `class/instance`.

**Alternatives**

If you're looking for alternative benchmarking tools for your JavaScript code, consider the following options:

* **Bench.js**: A lightweight benchmarking library that provides a simple API for running microbenchmarks.
* **Benchmark.js**: A popular benchmarking library that supports a wide range of test cases and features.
* **JIT-benchmark**: A benchmarking tool specifically designed to measure JavaScript engine's Just-In-Time (JIT) compilation performance.

Related benchmarks:

Slice vs Splice vs Shift in cycle (version: 0)

Compares the speed for removing 2 items from the beginning of an array

Comparing performance of: array.slice() vs array.splice() vs array.shift()

Created: 2 years ago by: Guest

Jump to the latest result

array.slice()

array.splice()

array.shift()

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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