Benchmark: for vs forEach - MeasureThat.net

Script Preparation code:

var testArray = [];

for (var i = 1; i <= 1000; i++) {
   testArray.push(i);
}

Tests:

for loop
for(var i = 0; i < testArray.length; i += 1) { testArray[i] += 1; }
forEach
testArray.forEach((item) => { item += 1; });
Map
testArray.map((item) => { item += 1; });

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
for loop
forEach
Map

Fastest: N/A

Slowest: N/A

Latest run results:

No previous 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 break down the provided benchmark and explain what's being tested.

**Benchmark Overview**

The benchmark compares three approaches: traditional `for` loop, `forEach`, and `map`. The test case is designed to iterate over an array of 1000 elements and perform a simple operation (incrementing each element) on each element.

**Options Compared**

1. **Traditional `for` Loop**: This approach uses a traditional `for` loop with an iterator (`i`) that iterates over the array indices.
2. **`forEach` Method**: This approach uses the `forEach` method, which is a built-in array method that executes a callback function for each element in the array.
3. **`map` Method**: This approach uses the `map` method, which returns a new array with the results of applying a provided function to every element in the original array.

**Pros and Cons**

* **Traditional `for` Loop**:
	+ Pros: Generally faster, more efficient, and easier to understand for small loops.
	+ Cons: Can be verbose, especially for larger loops. Requires manual incrementation of the iterator index.
* **`forEach` Method**:
	+ Pros: Concise, easy to read, and expressive. Eliminates the need to manually manage indices.
	+ Cons: May incur overhead due to function call and return values. Can be slower than traditional `for` loops for large arrays.
* **`map` Method**:
	+ Pros: Returns a new array with transformed elements, eliminating the need for indexing and manual incrementation. Can be faster than `forEach` for large arrays.
	+ Cons: Creates a new array, which can consume more memory. May incur overhead due to function call and return values.

**Library Used**

There is no library used in this benchmark. The code relies on built-in JavaScript methods (`for`, `forEach`, and `map`) and arrays.

**Special JS Feature or Syntax**

None of the approaches specifically utilize any special JavaScript features or syntax, such as async/await, promises, or ES6+ features like destructuring or template literals.

**Alternative Approaches**

Other alternatives to consider for this benchmark include:

* Using a custom iterator function with `for...of` loop
* Utilizing Web Workers or parallel processing for concurrent execution
* Employing more advanced array methods like `reduce`, `filter`, or `every`
* Implementing a custom loop using recursion or a generator function

Keep in mind that these alternatives may not be applicable to this specific use case, and their performance would depend on the specific requirements and constraints.

Related benchmarks:

for vs forEach (version: 0)

Comparing performance of: for loop vs forEach vs Map

Created: 8 years ago by: Guest

Jump to the latest result

for loop

forEach

Map

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):