Benchmark: Filter with .filter(), for loop, for in, reduce

Script Preparation code:

var arr = [1,2,3,4,5,6,7,8,9,0], farr;

Tests:

Filter
farr = arr.filter((item) => { return (item>4); });
For Loop
for (let i=0,len=arr.length;i<len;i++) { if (arr[i]<5) continue; farr.push(arr[i]); }
For Loop 2
for (let i=0,len=arr.length;i<len;i++) { if (arr[i]>4) farr.push(arr[i]); }
For In
for (var i in arr) { if (arr[i]>4) farr.push(arr[i]); }
Reduce
farr = arr.reduce((a, val) => { if (val > 4) a.push(val); return a; }, []);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Filter
For Loop
For Loop 2
For In
Reduce

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

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

LLMs can make mistakes. Check important info.

Let's break down the provided JSON benchmark definition and test cases.

**Benchmark Definition**

The provided JSON defines a single benchmark with four different test cases:

* "Filter" (using JavaScript's `filter()` method)
* "For Loop"
* "For Loop 2" (similar to the first, but with some differences)
* "For In" (using JavaScript's `for...in` loop)

**Script Preparation Code**

The script preparation code is used to prepare the test data before running each test case. For this benchmark, it initializes an array `arr` containing integers from 1 to 9 and then assigns the result of a function to a variable `farr`.

**Html Preparation Code**

There is no HTML preparation code provided in this benchmark.

**Test Cases**

Each test case defines a specific JavaScript code snippet that will be executed on the same data (`farr`). The test cases are:

1. **Filter**: This test case uses the `filter()` method to create a new array with only the elements greater than 4 from the original array.
2. **For Loop**: This test case uses a traditional `for` loop to iterate over the array and push elements greater than 4 to a new array.
3. **For Loop 2**: Similar to the first one, but with some differences (not specified in the benchmark definition).
4. **For In**: This test case uses the `for...in` loop to iterate over the array's properties and push elements greater than 4 to a new array.

**JavaScript Libraries**

There is no explicit JavaScript library mentioned in this benchmark.

**Special JS Features/Syntax**

The only special syntax used in this benchmark is the use of arrow functions (`(item) => { ... }`), which are supported by most modern JavaScript engines. There are also some differences between `For Loop 2` and the first `For Loop`, but they are not specified in detail.

**Pros and Cons**

Here's a brief overview of each approach:

* **Filter**: Pros: Efficient, concise, and easy to read. Cons: May not be as performant for very large arrays.
* **For Loop**: Pros: Can be more intuitive and easier to debug for some developers. Cons: Can be slower and more verbose than `filter()`.
* **For Loop 2** (and **For In**): Pros: Similar to traditional loops, but with some differences that might make them more suitable for certain use cases. Cons: May not be as efficient or concise as the other two approaches.

**Other Alternatives**

Some alternative approaches could include:

* Using `map()` instead of `filter()` or traditional loops.
* Using a library like Lodash to simplify the filtering process.
* Using a different data structure, such as a Set or Map, to improve performance.

Keep in mind that these alternatives would depend on specific requirements and use cases.

Related benchmarks:

Filter with .filter(), for loop, for in, reduce (version: 0)

Comparing performance of: Filter vs For Loop vs For Loop 2 vs For In vs Reduce

Created: 2 years ago by: Guest

Jump to the latest result

Filter

For Loop

For Loop 2

For In

Reduce

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

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