Benchmark: for vs for_of vs foreach vs map

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){ someFn(item); })
for
for (var i = 0, len = arr.length; i < len; i++) { someFn(arr[i]); }
map
arr.map(item => someFn(item))
for_of
for (var item of arr) { someFn(item); }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
foreach
for
map
for_of

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/107.0.0.0 Safari/537.36

Browser/OS: Chrome 107 on Windows

View result in a separate tab

Test name	Executions per second
foreach	15130.8 Ops/sec
for	7778.3 Ops/sec
map	14449.2 Ops/sec
for_of	15378.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into the provided benchmarking data.

**Benchmark Definition**
The provided JSON represents a JavaScript microbenchmark test, which compares the performance of four different iteration methods: `for`, `for_of`, `foreach`, and `map`. The script preparation code defines an array `arr` with 1000 elements, each initialized with a unique value. A function `someFn` is defined to multiply each element by 3 and 8.

**Iteration Methods Compared**
The test compares the performance of four iteration methods:

1. **for**: This method uses a traditional `for` loop with an index variable `i`.
2. **foreach**: This method uses the `forEach` method to iterate over the array, which is equivalent to a traditional `for` loop.
3. **map**: This method uses the `map` method to create a new array with transformed elements from the original array.
4. **for_of**: This method uses the `for...of` loop syntax to iterate over the array.

**Pros and Cons of Each Approach**

* **For Loop**:
	+ Pros: Control over iteration variables, easy to understand for beginners.
	+ Cons: Can be verbose, slower performance compared to other methods.
* **ForEach Method**:
	+ Pros: Easy to use, concise syntax, and often preferred by developers due to its readability.
	+ Cons: May not provide direct access to the index variable, which can limit optimization opportunities.
* **Map Method**:
	+ Pros: Creates a new array with transformed elements, avoids mutation of the original array, and is concise.
	+ Cons: Can be slower than other methods due to array creation and method invocation overhead. Also, may not optimize well for large arrays or nested loops.
* **For Of Loop**:
	+ Pros: Provides direct access to the index variable, which can lead to better optimization opportunities.
	+ Cons: May require more cognitive effort for developers who are new to this syntax.

**Library and Special JS Features**

The `forEach` method uses the built-in `Array.prototype.forEach` method, which is a standard JavaScript method. The `map` method also uses a standard JavaScript method from the `Array.prototype`. There are no special JavaScript features or syntax used in these benchmarks.

**Alternatives**
Other iteration methods that could be included in this benchmark include:

* `while` loop
* `for-in` loop (although less common)
* **Async Iteration**: This is an asynchronous iteration approach, which can provide better performance for large arrays and nested loops. However, it requires a more complex setup and may not be suitable for all use cases.
* **Web Workers**: This approach involves using Web Workers to perform the iteration in parallel, which can significantly improve performance on multi-core systems. However, this approach is more complex and requires a deeper understanding of web development.

Keep in mind that the choice of iteration method depends on the specific requirements of the project, such as readability, performance, and maintainability.

Related benchmarks:

for vs for_of vs foreach vs map (version: 0)

Comparing performance of: foreach vs for vs map vs for_of

Created: 3 years ago by: Guest

Jump to the latest result

foreach

for

map

for_of

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):