Benchmark: For vs Foreach manu

HTML Preparation code:

<!--your preparation HTML code goes here-->

Script Preparation code:

/*your preparation JavaScript code goes here
To execute async code during the script preparation, wrap it as function globalMeasureThatScriptPrepareFunction, example:*/
let test = 0;

function globalMeasureThatScriptPrepareFunction() {
    test = Math.random();
}

const ar = Array(100000);

Tests:

FOR
for (let i= 0; i < ar.length; i++) { globalMeasureThatScriptPrepareFunction(); }
FOREACH
ar.forEach(() => { globalMeasureThatScriptPrepareFunction(); });

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
FOR
FOREACH

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/132.0.0.0 Safari/537.36 OPR/117.0.0.0

Browser/OS: Opera 117 on Windows

View result in a separate tab

Test name	Executions per second
FOR	1534.8 Ops/sec
FOREACH	19818.9 Ops/sec

Autogenerated LLM Summary (model gpt-4o-mini, generated one month ago):

LLMs can make mistakes. Check important info.

The benchmark defined in the provided JSON compares two different looping techniques in JavaScript: the traditional `for` loop and the `forEach` method. Both of these methods are used to iterate over elements in an array (`ar`), which contains 100,000 entries, but they do it in different ways.

### Comparison of Options

1. **FOR Loop**:
   - **Benchmark Definition**: 
     ```javascript
     for (let i= 0; i < ar.length; i++) {
         globalMeasureThatScriptPrepareFunction();
     }
     ```
   - **Pros**:
     - The `for` loop is straightforward and a commonly used iteration method.
     - It allows fine-grained control over the loop iteration (e.g., you can easily manipulate the index).
     - It's slightly more performant in some cases, especially in scenarios where performance at scale is critical.
   - **Cons**:
     - It can lead to more verbose code since you need to manage the loop variable and the exit condition.

2. **forEach Method**:
   - **Benchmark Definition**:
     ```javascript
     ar.forEach(() => {
         globalMeasureThatScriptPrepareFunction();
     });
     ```
   - **Pros**:
     - The `forEach` method is more concise and can improve readability. It's clear that you are performing an operation on each item in the array without managing loop counters.
     - It is inherently safer from errors related to index management and off-by-one errors.
   - **Cons**:
     - The `forEach` method does not support breaking out of the loop or using `return` to exit early (though this can be mitigated with `some` or `every` in some scenarios).
     - In performance-sensitive applications, it may be slower than a traditional `for` loop, as it introduces a function scope with each iteration.

### Library Usage

In this benchmark, there is no external library being used. The code operates using standard JavaScript features. The function `globalMeasureThatScriptPrepareFunction` is defined in the Script Preparation Code and is executed within both test cases to account for any asynchronous or additional processing that would affect the timing of iterations.

### JavaScript Features/Syntax

No special JavaScript features are used that require explanation beyond standard looping constructs. Both `for` and `forEach` methods are considered core JavaScript syntax.

### Performance Results

The benchmark results show a significant difference in execution speed between the two methods:

- **forEach**: 19,818.94 executions per second
- **FOR**: 1,534.81 executions per second

This demonstrates that, in this particular case and environment (using Opera 117 on Windows Desktop), the `forEach` method outperforms the traditional `for` loop by a large margin.

### Alternatives

Other alternatives to iterating through an array in JavaScript include:

- **Classic `for` loop**: As analyzed above, suitable for performance-critical sections.
- **`for...of` loop**: Provides a clear and concise way to iterate over iterable objects (like arrays) while maintaining readability.
  ```javascript
  for (const item of ar) {
      globalMeasureThatScriptPrepareFunction();
  }
  ```
- **`map` or `reduce`**: These methods are also used to iterate through arrays while performing transformations or aggregations, though they're primarily for creating new arrays/types, which is not applicable for simple iteration.

### Conclusion

Ultimately, in scenarios where performance and handling of large datasets are critical, developers might choose traditional loops, while readability and ease of use might make `forEach` preferable in other contexts. Each method has its advantages and should be selected based on the specific requirements of the task at hand.

Related benchmarks:

For vs Foreach manu (version: 1)

Comparing performance of: FOR vs FOREACH

Created: one month 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 gpt-4o-mini, generated one month ago):