Benchmark: Array loop vs foreach

Script Preparation code:

   var arr = [];
    for (var i = 0; i < 1000; i++) {
      arr[i] = i;
    }
  
    function someFn(i) {
      return i * 3 * 8;
    }

Tests:

foreach
arr.forEach(function (item){ console.log("hey") })
for
for (var i = 0, len = arr.length; i < len; i++) { console.log("hey") }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
foreach
for

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 2 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/108.0.0.0 Safari/537.36

Browser/OS: Chrome 108 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
foreach	435.7 Ops/sec
for	430.8 Ops/sec

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

LLMs can make mistakes. Check important info.

I'd be happy to explain what's being tested in the provided benchmark.

**What is being tested?**

The benchmark compares two approaches: using `Array.prototype.forEach()` and using a traditional `for` loop (also known as a "forEach-less" approach) to iterate over an array. The test case creates an array of 1000 elements, populates it with values from 0 to 999, and then defines a function `someFn(i)` that takes an element `i` as input.

**Options compared:**

The benchmark compares two options:

1. **Array.prototype.forEach()**: This is the first option. It uses the `forEach()` method to iterate over the array, which invokes a callback function for each element in the array.
2. **Traditional "forEach-less" approach**: This is the second option. Instead of using `forEach()`, it uses a traditional `for` loop to iterate over the array, accessing each element by its index.

**Pros and Cons:**

* **Array.prototype.forEach():**
	+ Pros:
		- Easier to write and read, as it abstracts away the iteration logic.
		- More concise code.
		- Can be more efficient for small arrays, as it avoids the overhead of a loop variable.
	+ Cons:
		- Less control over the iteration process (e.g., no ability to break or continue the loop).
		- May not work well with large arrays or complex logic.
* **Traditional "forEach-less" approach:**
	+ Pros:
		- More control over the iteration process (e.g., ability to break or continue the loop).
		- Can be more efficient for large arrays or complex logic, as it allows for explicit loop termination conditions.
	+ Cons:
		- More verbose code, which can make it harder to read and maintain.

**Library:**

The benchmark uses the `Array.prototype.forEach()` method, which is a built-in JavaScript method that iterates over an array. The purpose of this method is to provide a concise way to execute a callback function for each element in an array, without requiring explicit loop logic.

**Special JS feature or syntax:**

There are no special JS features or syntax used in this benchmark.

**Other alternatives:**

If you wanted to compare other iteration approaches, some alternative methods could be:

* Using `Array.prototype.reduce()`
* Using `Array.prototype.every()`
* Using a `for...of` loop (introduced in ECMAScript 2015)
* Using a `while` loop or recursion

However, the traditional "forEach-less" approach and `Array.prototype.forEach()` are two of the most common and widely used iteration methods in JavaScript.

Related benchmarks:

Array loop vs foreach (version: 0)

Comparing performance of: foreach vs for

Created: 2 years ago by: Guest

Jump to the latest result

foreach

for

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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