Benchmark: slice vs filter23

Script Preparation code:

var test=Array.from({length: 20000},()=>Math.random())

Tests:

slice
test.slice(0,50)
filter
test.filter((e,i)=>i<=50)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
slice
filter

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) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/119.0.0.0 Safari/537.36 Edg/119.0.0.0

Browser/OS: Chrome 119 on Windows

View result in a separate tab

Test name	Executions per second
slice	8505430.0 Ops/sec
filter	15921.4 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 and explain what's tested in this specific benchmark.

**Benchmark Purpose:**
The purpose of this benchmark is to compare the performance of two common array methods in JavaScript: `Array.prototype.slice()` and `Array.prototype.filter()`. These methods are often used to extract a subset of elements from an array.

**Options Compared:**

1. **`slice()`**: This method returns a new array containing all elements from the original array, starting from the specified index (in this case, 0) up to, but not including, the specified end index (50). The `slice()` method is generally considered fast because it doesn't modify the original array and can be optimized by browsers.
2. **`filter()`**: This method creates a new array with all elements that pass the test implemented by the provided function (in this case, `(e,i)=>i<=50`). The `filter()` method modifies the original array by creating a new one with the filtered elements.

**Pros and Cons:**

*   `slice()`: Pros:
    *   Fast and efficient
    *   Does not modify the original array
    *   Can be optimized by browsers
*   `slice()`: Cons:
    *   Creates a new array, which can lead to increased memory usage
*   `filter()`**: Pros:
    +  Creates a new array with filtered elements, allowing for in-place filtering
    -  May be slower due to the creation of a new array
*   `filter()`**: Cons:
    *   Modifies the original array

**Library:**
There are no specific libraries used in this benchmark. Both `slice()` and `filter()` are native methods provided by JavaScript.

**Special JS Feature or Syntax:**
None mentioned in the provided benchmark definition.

**Other Considerations:**

*   This benchmark only compares two methods for extracting a subset of elements from an array. Other methods, like `Array.prototype.map()`, `Array.prototype.forEach()`, or `Array.prototypereduce()`, are not tested.
*   The size of the input array (20,000 elements) is relatively small compared to typical use cases.

**Alternatives:**

1.  **`Array.prototype.reduce()`**: Instead of using `slice()` or `filter()`, you could use `Array.prototype.reduce()` with a custom function that iterates over the array and accumulates values in an accumulator.
2.  **Custom implementation**: You can write your own optimized implementation for extracting a subset of elements from an array, which may be more efficient than using existing methods like `slice()` or `filter()`.
3.  **Other libraries**: Depending on the specific use case, you might consider using a library like Lodash, which provides various utility functions for working with arrays.

I hope this explanation helps! Let me know if you have any further questions.

Related benchmarks:

slice vs filter23 (version: 0)

Comparing performance of: slice vs filter

Created: one year ago by: Guest

Jump to the latest result

slice

filter

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):