Benchmark: array for vs foreach

HTML Preparation code:

<script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.5/lodash.core.js"></script>

Script Preparation code:

var a = ['hello', 'a', 'bc', '5', '6','7'];

Tests:

array foreach
var b=''; a.forEach(c => b+=c)
For
var b =''; for (var i =0,n=a.length; i<n;i++) b+=a[i];

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
array foreach
For

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 break down the provided benchmark and explain what's being tested, compared, and their pros and cons.

**Benchmark Overview**

The benchmark compares two approaches to iterate over an array:

1. `forEach` method (using the spread operator)
2. Traditional `for` loop

**Comparison**

In the first test case (`array foreach`), a variable `b` is initialized as an empty string, and then the `forEach` method is used to concatenate strings from array `a` to `b`. In the second test case (`For`), a traditional `for` loop is used to achieve the same result.

**Options Compared**

* **Using `forEach` method**: This approach uses the spread operator (`...`) to iterate over the array and concatenate strings.
	+ Pros:
		- Concise and readable code
		- Easy to understand and maintain
		- Does not require explicit looping or indexing
	+ Cons:
		- Performance may be slower due to string concatenation in a loop
		- May not be as efficient for large arrays due to the overhead of function calls
* **Traditional `for` loop**: This approach uses an explicit loop with iteration and indexing.
	+ Pros:
		- Can be faster for large arrays due to optimized looping mechanisms
		- Less memory allocation and garbage collection overhead
	+ Cons:
		- More verbose and less readable code
		- May require more maintenance effort due to the need to manage indices

**Library**

In the benchmark, Lodash is used as a dependency. Specifically, `lodash.core.js` provides the `forEach` method implementation.

Lodash's `forEach` method is a wrapper around the native JavaScript `Array.prototype.forEach` method, providing additional features and error handling for better usability.

**Special JS Features or Syntax**

The benchmark does not use any special JavaScript features or syntax that would require explanation beyond the basic concepts.

**Other Alternatives**

For this specific comparison, other alternatives could be:

* Using `for...of` loop with a spread operator (`...`) to iterate over the array.
* Utilizing libraries like `lodash` or `ramda` which provide optimized implementations of iteration and concatenation functions.

However, for this particular benchmark, Lodash's implementation of `forEach` is the most relevant alternative.

**Benchmark Preparation Code**

The preparation code provided sets up the environment by:

1. Defining array `a` with sample strings.
2. Including the Lodash dependency (`lodash.core.js`) via a CDN link.

These steps ensure that the benchmark can execute correctly and compare the two iteration approaches.

I hope this explanation helps!

Latest run results:

Run details: (Test run date: 3 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.106 YaBrowser/21.6.0.1108 Yowser/2.5 Safari/537.36

Browser/OS: Yandex Browser 21 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
array foreach	6451555.0 Ops/sec
For	1794313.5 Ops/sec

Related benchmarks:

array for vs foreach (version: 2)

Compare the new ES6 spread operator with the traditional concat() method

Comparing performance of: array foreach vs For

Created: 6 years ago by: Registered User

Jump to the latest result

array foreach

For

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):