Benchmark: double filter vs foreach

Script Preparation code:


var arr = [];
for(i=0; i<100; i++){
  Math.random() > .5 ? arr.push({is_group: true}) : arr.push({is_group: false})
}

Tests:

filter
const a = arr.filter(i => i.is_group) const b = arr.filter(i => !i.is_group)
forEach
const a = []; const b = []; arr.forEach(i => { if (i.is_group) { a.push(i) } else { b.push(i) } })

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
filter
forEach

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.

I'd be happy to help you understand the provided JavaScript microbenchmark on MeasureThat.net.

**What is being tested?**

The benchmark tests the performance of two different approaches to filter an array in JavaScript:

1. Using the `filter()` method with a callback function.
2. Using the `forEach()` method with a callback function and conditional statements.

**Options compared:**

* **`filter()` method**: This approach uses the `Array.prototype.filter()` method, which takes a callback function as its first argument and returns a new array containing only the elements for which the callback function returns `true`.
* **`forEach()` method**: This approach uses the `Array.prototype.forEach()` method, which executes a provided function once for each element in an array. In this case, the function is modified to push elements to two separate arrays based on their properties.

**Pros and cons of each approach:**

* **`filter()` method:**
	+ Pros:
		- More concise and expressive code.
		- Less memory-intensive since it returns a new array without modifying the original.
	+ Cons:
		- May be slower than the `forEach()` method due to the overhead of creating a new array.
* **`forEach()` method:**
	+ Pros:
		- Can be more efficient for large datasets since it avoids the overhead of creating a new array.
	+ Cons:
		- Requires modifying the original array, which may not be desirable in some cases.

**Library and its purpose**

There is no specific library mentioned in this benchmark. However, `Array.prototype.filter()` and `Array.prototype.forEach()` are built-in methods in JavaScript, so no additional libraries are required to use these approaches.

**Special JS feature or syntax**

There are no special features or syntaxes used in this benchmark that would require additional explanation. The code uses standard JavaScript syntax and does not include any experimental features like async/await or classes.

**Other alternatives**

In general, other alternatives for filtering an array might include:

* `map()` method: While not as efficient as `filter()`, the `Array.prototype.map()` method can be used to create a new array with filtered elements.
* `reduce()` method: This method is less commonly used for filtering arrays but could be considered as an alternative approach.

However, these alternatives would likely have different performance characteristics and may not offer any significant benefits over the `filter()` and `forEach()` methods in this specific benchmark.

Related benchmarks:

double filter vs foreach (version: 0)

Comparing performance of: filter vs forEach

Created: 5 years ago by: Guest

Jump to the latest result

filter

forEach

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):