Benchmark: for vs foreach vs some vs every vs for..of vs map es6

Script Preparation code:

var array = Array(100).fill(0);

Tests:

for
for (let i = 0; i < array.length; i++) { array[i]; }
foreach
array.forEach(i => { array[i]; });
some
array.some(i => { array[i]; });
every
array.every(i => { array[i]; });
for..of
for (const i of array) { array[i]; }
map
array.map(a => a);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
for
foreach
some
every
for..of
map

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:109.0) Gecko/20100101 Firefox/111.0

Browser/OS: Firefox 111 on Windows

View result in a separate tab

Test name	Executions per second
for	9476265.0 Ops/sec
foreach	5030118.5 Ops/sec
some	4760327.0 Ops/sec
every	767291264.0 Ops/sec
for..of	1358894.2 Ops/sec
map	2761827.5 Ops/sec

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

LLMs can make mistakes. Check important info.

I'll provide an explanation of the provided benchmark, its options, and considerations.

**Overview**

The MeasureThat.net benchmark compares the performance of different loop iteration methods in JavaScript: `for`, `foreach`, `some`, `every`, `for..of`, and `map`. The goal is to determine which method is the fastest for iterating over an array of a specific size (100 elements).

**Loop Options**

1. **`for`**: This traditional loop uses a manual index variable (`i`) that increments on each iteration.
	* Pros: Simple, widely supported, and works in most browsers.
	* Cons: Can be error-prone due to off-by-one errors or incorrect indexing.
2. **`foreach`**: This loop iterates over the array using a callback function for each element.
	* Pros: Concise, readable, and avoids manual indexing issues.
	* Cons: May have performance overhead due to the additional function call.
3. **`some`**: This loop returns true as soon as the condition is met, and false if not.
	* Pros: Can be faster than `for` or `foreach` for arrays with a small number of elements.
	* Cons: Returns early and might not cover all array elements.
4. **`every`**: This loop returns true only if the condition is met for all elements; otherwise, it returns false.
	* Pros: Similar to `some`, but covers the entire array.
	* Cons: Slower than `for` or `foreach` due to its strict evaluation.
5. **`for..of`**: This loop uses a modern, built-in syntax to iterate over arrays.
	* Pros: Concise, readable, and optimized for performance.
	* Cons: Requires modern browsers that support this feature (Firefox 111 in this case).
6. **`map`**: This loop applies a transformation function to each element of the array and returns a new array.
	* Pros: Can be used as a standalone operation or combined with other loops.
	* Cons: Creates a new array, which may not be necessary for simple iteration.

**Library Considerations**

In this benchmark, none of the loops require a specific library beyond the standard JavaScript features. However, some browsers might have additional libraries or extensions that can affect performance.

**Special JavaScript Features and Syntax**

This benchmark uses modern JavaScript features like arrow functions (`=>`), destructuring assignment (`const i of array`), and template literals (e.g., `\r\n`). These features are widely supported in modern browsers but may not work in older versions. If the goal is to ensure compatibility across various browsers, the `for` loop with a traditional function definition might be a better choice.

**Alternatives**

If you need to benchmark other loop iteration methods or consider alternative approaches, you can explore:

1. **Cycles**: Instead of iterating over an array, cycles can be used to traverse a data structure.
2. **Generators**: Generators are a special type of function that allows for lazy iteration and can be more memory-efficient than arrays.
3. **Async/await loops**: Modern JavaScript supports async/await syntax, which can simplify asynchronous iteration.

Keep in mind that the performance differences between these approaches may vary depending on the specific use case, array size, and browser version. The MeasureThat.net benchmark provides a good starting point for understanding performance characteristics of different loop iteration methods in modern JavaScript.

Related benchmarks:

for vs foreach vs some vs every vs for..of vs map es6 (version: 1)

Compare loop performance

Comparing performance of: for vs foreach vs some vs every vs for..of vs map

Created: one year ago by: Registered User

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for

foreach

some

every

for..of

map

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):