Benchmark: for loop push vs mapFilter

Script Preparation code:

var myLargeArray = [];
for (var i = 0; i < 1 << 12; i++) {
  myLargeArray.push(i); 
}

Tests:

for loop push
const resultsArr = [] myLargeArray.forEach(function(element) { if (element % 2 === 0) { resultsArr.push(element) } });
map filter
myLargeArray .map((element) => (element % 2 === 0 ? element : null)) .filter(evenNumber => (evenNumber !== null));

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
for loop push
map filter

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 28 days ago):

LLMs can make mistakes. Check important info.

Let's dive into the explanation.

**Benchmark Definition JSON**

The provided JSON represents a benchmark named "for loop push vs mapFilter". This benchmark is designed to compare the performance of two approaches: using a traditional for loop with array push and using the Array.prototype.map() method followed by the Array.prototype.filter() method.

**Options being compared**

The two options being compared are:

1. **For loop with array push**: This approach uses a traditional for loop to iterate over the array and use the push() method to add elements to the end of the array.
2. **Map() + Filter()**: This approach uses the Array.prototype.map() method to create a new array with filtered values, followed by the Array.prototype.filter() method to remove null values from the resulting array.

**Pros and Cons**

* **For loop with array push**:
	+ Pros: Can be more memory-efficient, as it only adds elements to the end of the array without creating intermediate arrays.
	+ Cons: Can be slower due to the overhead of the for loop and the push() method, which creates a new element and adds it to the end of the array.
* **Map() + Filter()**:
	+ Pros: Typically faster, as it leverages optimized native methods that are implemented in the browser's JavaScript engine.
	+ Cons: Creates intermediate arrays, which can lead to increased memory usage.

**Library and Purpose**

The Array.prototype.map() method and Array.prototype.filter() method are built-in JavaScript library functions that operate on arrays. They provide a concise way to perform operations on array elements without iterating over the entire array using traditional loops.

In this benchmark, these methods are used to filter out null values from the resulting array after applying a transformation to each element.

**Special JS feature or syntax**

There is no special JavaScript feature or syntax used in this benchmark. The code uses standard JavaScript concepts and built-in methods.

**Other alternatives**

If you wanted to test different approaches, you could consider the following alternatives:

1. Using a while loop instead of a for loop.
2. Using a different array manipulation method, such as reducing() or every().
3. Adding additional operations after filtering the array, such as sorting or concatenating with another array.

Keep in mind that these alternative approaches may not be directly comparable to the original two options being tested (for loop + push and Map() + Filter()).

Latest run results:

Run details: (Test run date: 5 years ago)

User agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/73.0.3683.103 Safari/537.36

Browser/OS: Chrome 73 on Windows 7

View result in a separate tab

Test name	Executions per second
for loop push	19920.5 Ops/sec
map filter	8533.9 Ops/sec

Related benchmarks:

for loop push vs mapFilter (version: 0)

Comparing performance of: for loop push vs map filter

Created: 5 years ago by: Registered User

Jump to the latest result

for loop push

map filter

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 28 days ago):