Benchmark: Small dataset - Reduce vs Filters

Script Preparation code:

var tabl = Array.from({ length: 30 }).map((value, i) => i)

Tests:

Reduce
const newArr = tabl.reduce((prevArr, currVal) => {if(currVal === 27) {return [currVal, ...prevArr]} else {return [...prevArr, currVal]}}, [])
Filter
const newArr = [...tabl.filter(e => e === 27),...tabl.filter(e => e !== 27)];

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Reduce
Filter

Fastest: N/A

Slowest: N/A

Latest run results:

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Autogenerated LLM Summary (model gemma2:9b, generated one year ago):

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This benchmark compares two approaches to filtering elements from an array: using the `reduce()` method and using the `filter()` method.

**Options Compared:**

* **`reduce()` Method:** This method iterates over each element in the array, accumulating a new array based on a provided function. In this case, the function checks if the current value is 27. If it is, it adds it to the beginning of the new array; otherwise, it adds it to the end.
* **`filter()` Method:** This method creates a new array containing only elements that pass a test defined by the provided function. Here, we use two separate `filter()` calls: one to select elements equal to 27 and another to select all other elements.

**Pros and Cons:**

* **Reduce():**
    * **Potential for Conciseness:** Can sometimes express complex logic in fewer lines of code.
    * **Can Be Less Efficient:** In this specific case, it involves iterating through the entire array twice (once for filtering and once for accumulating). 
* **Filter():**
    * **More Direct Filtering:** Explicitly designed for selecting elements based on a condition.
    * **Potentially More Efficient:**  Generally performs better than `reduce()` for simple filtering tasks because it doesn't require accumulating an intermediate result.

**Other Considerations:**

* **Array Size:** The performance difference between these approaches might be more pronounced with larger arrays.
* **Specificity of the Task:** If your goal is simply to filter elements based on a condition, `filter()` is usually the clearer and more efficient choice.

**Alternatives:**

* **Manually Iterating:** You could also use a `for` loop to iterate through the array and build a new array based on your criteria. However, this approach often leads to less readable code compared to using built-in methods like `reduce()` and `filter()`.

Related benchmarks:

Small dataset - Reduce vs Filters (version: 0)

Comparing performance of: Reduce vs Filter

Created: 4 years ago by: Guest

Jump to the latest result

Reduce

Filter

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

Autogenerated LLM Summary (model gemma2:9b, generated one year ago):