Benchmark: for vs array functions

Script Preparation code:

var arr='giyrxgfoyugrxeupqzuehfgfccsydgfpxwieuhqzuiehfuiegfyuegfpegrygrypiop634927chmiuqefdyiqdetfcityrfiwecfiuegciquegiyrxgfoyugrxeupqzuehfgfccsydgfpxwieuhqzuiehfuiegfyuegfpegrygrypiop634927chmiuqefdyiqdetfcityrfiwecfiuegciquegiyrxgfoyugrxeupqzuehfgfccsydgfpxwieuhqzuiehfuiegfyuegfpegrygrypiop634927chmiuqefdyiqdetfcityrfiwecfiuegciquegiyrxgfoyugrxeupqzuehfgfccsydgfpxwieuhqzuiehfuiegfyuegfpegrygrypiop634927chmiuqefdyiqdetfcityrfiwecfiuegciquegiyrxgfoyugrxeupqzuehfgfccsydgfpxwieuhqzuiehfuiegfyuegfpegrygrypiop634927chmiuqefdyiqdetfcityrfiwecfiuegciquegiyrxgfoyugrxeupqzuehfgfccsydgfpxwieuhqzuiehfuiegfyuegfpegrygrypiop634927chmiuqefdyiqdetfcityrfiwecfiuegciquegiyrxgfoyugrxeupqzuehfgfccsydgfpxwieuhqzuiehfuiegfyuegfpegrygrypiop634927chmiuqefdyiqdetfcityrfiwecfiuegciquegiyrxgfoyugrxeupqzuehfgfccsydgfpxwieuhqzuiehfuiegfyuegfpegrygrypiop634927chmiuqefdyiqdetfcityrfiwecfiuegciqueieuhqzuiehfuiegfyuegfpegrygrypiop634927chmiuqefdyiqdetfcityrfiwecfiuegciquegiyrxgfoyugrxeupqzuehfgfccsydgfpxwieuhqzuiehfuiegfyui'.split('');
var a;

Tests:

for
const k = (b) => {a=b} for(let i=0; i < 1000; ){k(arr[i++])};
foreach
arr.forEach((b)=>{a=b});

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
for
foreach

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 28 days ago):

LLMs can make mistakes. Check important info.

Measuring the performance of different JavaScript iteration techniques is an essential task for any web developer or JavaScript enthusiast.

**Benchmark Definition**

The provided benchmark definition json describes two individual test cases: "for" and "foreach". Both test cases aim to measure the performance of iterating over an array using two different methods.

1. **Test Case 1: "for"`**
	* The `Benchmark Definition` script uses a traditional for loop (`for(let i=0; i < 1000; ){k(arr[i++])};`) with a function `k` that takes an element from the array and assigns it to variable `a`.
2. **Test Case 2: "foreach"`**
	* The `Benchmark Definition` script uses the `forEach` method on the `arr` array, which iterates over each element in the array and calls a provided callback function (in this case, `(b)=>{a=b};`) for each iteration.

**Options Compared**

The benchmark compares two options:

1. **Traditional For Loop (`for`)**: This is a manual loop that increments a counter variable until it reaches the end of the array.
2. **Array Method `forEach`**: This method iterates over each element in the array and calls a callback function for each iteration.

**Pros and Cons**

**For Loop (`for`) Pros:**

* More control over the iteration process
* Can be used with any type of data structure (not limited to arrays)

Cons:

* Requires manual increment of counter variable
* May lead to off-by-one errors or other mistakes if not implemented carefully

**Array Method `forEach` Pros:**

* Elegant and concise syntax
* No need for manual loop logic
* Built-in support in modern JavaScript engines

Cons:

* Less control over the iteration process compared to a traditional for loop
* Only suitable for arrays (or iterable objects)

**Other Considerations**

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

* **Performance**: In general, array methods like `forEach` are faster than traditional for loops because they are implemented in optimized C++ code. However, this difference is usually negligible unless you're dealing with very large arrays or performance-critical code.
* **Readability**: Array methods like `forEach` can make your code more concise and readable, especially when working with large datasets.

**Library Used**

In the provided benchmark definition json, no specific library is used. However, it's worth noting that some JavaScript engines (e.g., V8) have built-in optimizations for array iteration, which may affect the performance difference between these two options.

**Special JS Feature or Syntax**

The `forEach` method in JavaScript is a built-in method for iterating over arrays and other iterable objects. It was introduced in ECMAScript 2015 (ES6).

**Alternatives**

If you need to iterate over data structures other than arrays, consider using:

1. **Traditional For Loop (`for`)**: Suitable for any type of data structure.
2. **Array Method `map`**, `filter`**: Designed for transforming and filtering arrays, respectively.
3. **Set**: A built-in object for storing unique values, with methods like `forEach`, `clear()`, etc.

In conclusion, the choice between a traditional for loop and an array method like `forEach` depends on your specific use case, performance requirements, and personal preference.

Latest run results:

Run details: (Test run date: 5 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/70.0.3538.102 Safari/537.36

Browser/OS: Chrome 70 on Windows

View result in a separate tab

Test name	Executions per second
for	5197.5 Ops/sec
foreach	9414.8 Ops/sec

Related benchmarks:

for vs array functions (version: 0)

Comparing performance of: for vs foreach

Created: 6 years ago by: Guest

Jump to the latest result

for

foreach

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):