Benchmark: forEach vs reduce vs map vs filter vs for --ali

Script Preparation code:

var arr = [];
for (var i = 0; i < 12345; i++) {
  arr[i] = i;
}

 var sumReduce = 0,
  sumFor = 0;

Tests:

reduce
sumReduce = arr.reduce((lastValue, item) => { return sumReduce += item; });
for
for (var j = 0,l=arr.length; j < l; j++) { sumFor += arr[j]; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
reduce
for

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 different methods for calculating the sum of numbers in an array:

* **`reduce`**: This method iterates through each element of the array, applying a function to accumulate a single result. The provided `reduce` implementation uses a simple accumulator (`sumReduce`) and adds each item from the array to it.
* **`for` loop**: This traditional approach explicitly iterates through the array using a counter variable (`j`).  In each iteration, it adds the current element (`arr[j]`) to the `sumFor`.

**Pros & Cons:**

* **`reduce`:** 
    * **Pros:** Concise and expressive, often considered more readable than explicit loops. Can be used for more complex operations beyond simple summation.  Leverages functional programming concepts.
    * **Cons:** Might perform slightly less efficiently in some cases compared to a well-optimized `for` loop due to the overhead of function calls.

* **`for` loop:** 
    * **Pros:** Can be highly optimized for performance, potentially outperforming `reduce` in benchmarks where efficiency is paramount. Direct control over iteration allows for fine-grained optimization.
    * **Cons:** Can be more verbose and less readable compared to `reduce`. Less adaptable for complex operations beyond simple summation.

**Other Considerations:**

* **Library Usage:** This benchmark doesn't involve any external libraries. 
* **Special JS Features:**  No special JavaScript features or syntax are used in these examples.

**Alternatives:**

* **`map`**: While not used in this benchmark, `map` could be used to create a new array with the sum of each element transformed in some way.
* **`filter`**: This method would only include elements meeting a specific condition, and wouldn't directly calculate a sum.
* **Built-in Array Methods:** JavaScript provides built-in methods like `Array.sum` or similar that might offer even more optimized solutions for summation.

The choice between these methods often depends on the specific context:

* For simple sums, `reduce` might be the most concise and readable option.
* If performance is critical, a carefully optimized `for` loop could be slightly faster.

Related benchmarks:

forEach vs reduce vs map vs filter vs for --ali (version: 0)

Comparing performance of: reduce vs for

Created: 5 years ago by: Registered User

Jump to the latest result

reduce

for

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):