Benchmark: Occurance with filter or forEach

Script Preparation code:

var arr = [2, 3, 1, 3, 4, 5, 3, 1];

Tests:

forEach
function getOccurrence(array, value) { var count = 0; array.forEach((v) => (v === value && count++)); return count; } console.log(getOccurrence(arr, 1));
filter
function getOccurrence(array, value) { return array.filter((v) => (v === value)).length; } console.log(getOccurrence(arr, 1));

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
forEach
filter

Fastest: N/A

Slowest: N/A

Latest 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 dive into the explanation of the provided benchmark.

**What is tested?**

The provided benchmark tests two approaches to find the occurrence of a specific value in an array: using `filter()` and using `forEach()`. Both approaches are implemented as separate functions (`getOccurrence`) that take an array and a value as input, and return the count of occurrences of the value.

**Options compared**

Two options are compared:

1. **`forEach()`**: This approach uses the `forEach()` method to iterate over the array. The callback function `(v) => (v === value && count++)` increments the `count` variable whenever it encounters a match.
2. **`filter()`**: This approach uses the `filter()` method to create a new array containing only the elements that match the condition `(v === value)`. The length of this filtered array is then returned as the count.

**Pros and Cons**

Here's a brief analysis of each approach:

* **`forEach()`**:
	+ Pros: Can be more intuitive for developers familiar with the `forEach()` method.
	+ Cons: May incur additional overhead due to iteration over the entire array, even if only one element matches.
* **`filter()`**:
	+ Pros: Can be more efficient since it returns a new array containing only the matching elements, reducing the number of iterations required.
	+ Cons: Requires a separate loop or method call to iterate over the filtered array and extract the count.

**Library usage**

In this benchmark, no external libraries are used. The `forEach()` and `filter()` methods are part of the standard JavaScript API.

**Special JS features/syntax**

None are explicitly mentioned in the provided code. However, it's worth noting that modern JavaScript features like ES6 classes, modules, or async/await syntax are not used in this benchmark.

**Other alternatives**

If the authors were to explore alternative approaches, they might consider:

* Using `reduce()` method instead of `forEach()`, which could provide a more concise solution.
* Implementing the solution using `Set` data structure, which could potentially offer better performance for large arrays.
* Utilizing WebAssembly or other low-level optimization techniques to further improve performance.

Overall, this benchmark provides a simple and straightforward way to compare the performance of two common array iteration methods in JavaScript.

Related benchmarks:

Occurance with filter or forEach (version: 0)

Comparing performance of: forEach vs filter

Created: 5 years ago by: Guest

Jump to the latest result

forEach

filter

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):