Benchmark: for / forEach - MeasureThat.net

Script Preparation code:

var array = new Array(100);

Tests:

for..of
for (var i = 0; i < array.length; i++) { console.log(array[i]); }
Array.forEach
array.forEach(function(i) { console.log(array[i]); });

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
for..of
Array.forEach

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 YaBrowser/24.1.0.0 Safari/537.36

Browser/OS: Yandex Browser 24 on Windows

View result in a separate tab

Test name	Executions per second
for..of	2723.3 Ops/sec
Array.forEach	4666835.5 Ops/sec

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 Definition**

The benchmark is testing two different approaches to iterate over an array:

1. **For loop with traditional `array.length`**: The first approach uses a traditional for loop, where the variable `i` iterates from 0 to `array.length - 1`, logging each element of the array.
2. **Array method `forEach`**: The second approach uses the `forEach` method provided by the Array prototype, which executes a callback function once for each element in the array, logging each element.

**Options Compared**

The two options being compared are:

* Traditional for loop with manual iteration (`array.length`)
* Array method `forEach`

**Pros and Cons of Each Approach**

1. **Traditional For Loop**:
	* Pros:
		+ More control over the iteration process
		+ Can be used with other data structures like objects or arrays with non-numeric indices
	* Cons:
		+ Requires manual incrementation of the loop variable (`i`)
		+ May have performance overhead due to unnecessary checks
2. **Array Method `forEach`**:
	* Pros:
		+ Concise and readable syntax
		+ Built-in optimization for performance
		+ Can be used with other data structures like arrays or objects
	* Cons:
		+ Less control over the iteration process
		+ May have a slight performance overhead due to function call overhead

**Library Used (if applicable)**

There is no library explicitly mentioned in the benchmark definition. However, the `forEach` method is a part of the Array prototype, which is a built-in JavaScript feature.

**Special JS Feature or Syntax**

The benchmark uses a traditional for loop with manual iteration (`array.length`). There are no special features or syntaxes used beyond this simple iteration pattern.

**Other Considerations**

When choosing between these two approaches, consider the following factors:

* Readability: If readability is crucial, `forEach` might be a better choice due to its concise syntax.
* Control: If you need fine-grained control over the iteration process, traditional for loop might be a better fit.
* Performance: Both methods have similar performance characteristics in most cases. However, if you're iterating over large arrays or performing complex operations, `forEach` with its built-in optimization might provide a slight edge.

**Alternative Approaches**

Other approaches to iterate over an array could include:

* For...of loop (similar to traditional for loop but with more modern syntax)
* Using `reduce()` method
* Using `map()` method (though it returns a new array, not modifying the original)

These alternatives might be worth considering in different scenarios or when working with specific data structures.

Related benchmarks:

for / forEach (version: 0)

Comparing performance of: for..of vs Array.forEach

Created: 2 years ago by: Guest

Jump to the latest result

for..of

Array.forEach

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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