Benchmark: filter vs slice - remove first

Script Preparation code:

var test=Array.from({length: 100},()=>Math.random())

Tests:

slice
test.slice(1)
filter
test.filter((e,i) => i !== 0)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
slice
filter

Fastest: N/A

Slowest: N/A

Autogenerated LLM Sumamry (model llama3.2:3b, generated 4 days ago):

LLMs can make mistakes. Check important info.

I'll explain the benchmark in detail, highlighting what's being tested, compared options, pros and cons, and other considerations.

**Benchmark Overview**

The provided JSON represents a JavaScript microbenchmark test case on MeasureThat.net. The benchmark is designed to compare the performance of two approaches: using the `slice` method versus using the `filter` method to remove elements from an array.

**Test Case Preparation Code**

The preparation code for the test case is defined in the "Script Preparation Code" field:
```javascript
var test = Array.from({ length: 100 }, () => Math.random());
```
This code creates a large array (`test`) with 100 random elements, using `Array.from` and `Math.random`. This initialization step is executed before running each benchmark iteration.

**Options Compared**

The two options being compared are:

1. **Slice Method**: The `slice` method takes an integer as its first argument, which specifies the starting index of the slice. In this case, `test.slice(1)` removes all elements from index 0 to 99.
2. **Filter Method**: The `filter` method takes a callback function that returns `true` for elements to include in the resulting array and `false` otherwise. In this case, `(e, i) => i !== 0` filters out elements at index 0.

**Pros and Cons**

**Slice Method:**

Pros:

* Generally faster, as it avoids creating a new array with unnecessary elements.
* Can be more efficient for large arrays, since it doesn't require iterating over all elements.

Cons:

* May not work correctly if the starting index is negative or greater than the length of the array.
* Returns a shallow copy of the original array, which can lead to unexpected behavior in some situations.

**Filter Method:**

Pros:

* More flexible and intuitive, as it allows for arbitrary filtering conditions.
* Works correctly even when the starting index is negative or greater than the length of the array.

Cons:

* May be slower due to the overhead of creating a new array with filtered elements.
* Can create unnecessary memory allocations if the filter condition returns `true` frequently.

**Other Considerations**

* The benchmark only measures the execution time of each method, without considering other factors like memory allocation or garbage collection.
* The test case doesn't account for edge cases like empty arrays or arrays with a single element.

**Library Usage**

There is no explicit library usage in this test case. However, `Array.from` and `Math.random` are built-in JavaScript functions that don't require external libraries to be executed.

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

There are no special JavaScript features or syntax used in this benchmark that would affect its execution or interpretation.

**Alternatives**

If you were to rewrite this benchmark, you could consider the following alternatives:

1. **Using `map` instead of `filter`:** Instead of using `filter`, you could use the `map` method to create a new array with filtered elements. However, this would require modifying the filter condition accordingly.
2. **Using an external library:** If you needed to perform more complex filtering operations, you might consider using an external library like Lodash or Underscore.js.
3. **Measuring memory allocation:** To get a better understanding of the performance characteristics, you could modify the benchmark to measure memory allocation and garbage collection overhead for each method.

Keep in mind that rewriting the benchmark would require careful consideration of the trade-offs between different approaches and the specific requirements of your use case.

Latest run results:

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

User agent: Mozilla/5.0 (X11; Linux x86_64; rv:98.0) Gecko/20100101 Firefox/98.0

Browser/OS: Firefox 98 on Linux

View result in a separate tab

Test name	Executions per second
slice	6836956.0 Ops/sec
filter	966775.6 Ops/sec

Related benchmarks:

filter vs slice - remove first (version: 0)

Comparing performance of: slice vs filter

Created: 2 years 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 Sumamry (model llama3.2:3b, generated 4 days ago):