Benchmark: for vs foreach vs some

Script Preparation code:

var array = new Array(100);

Tests:

for
for (var i = 0; i < array.length; i++) { array; }
foreach
array.forEach(function(item, index) { array; });
some
array.some(function(item, index) { array; });

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
for
foreach
some

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 26 days ago):

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks!

**Benchmark Definition**

The benchmark definition JSON represents a simple loop comparison between three approaches: `for`, `forEach`, and `some`. The script preparation code initializes an array with 100 elements, which will be used as the test data.

The HTML preparation code is empty, indicating that this benchmark doesn't rely on any specific HTML structure or content.

**Options Compared**

In this benchmark, we have three options compared:

1. **`for` loop**: A traditional `for` loop uses an iterator variable to iterate over the array elements.
2. **`forEach` loop**: The `forEach` method is a built-in function in JavaScript that executes a callback function once for each element in an array.
3. **`some` loop**: The `some` method returns `true` as soon as the predicate (a function) returns `true`. It doesn't guarantee to iterate over all elements.

**Pros and Cons**

Here's a brief summary of the pros and cons of each approach:

*   **`for` Loop**:
    *   Pros: Can be faster for large arrays because it avoids the overhead of function calls.
    *   Cons: Tightly coupled with array indices, can lead to off-by-one errors, and less readable when dealing with complex logic.
*   **`forEach` Loop**:
    *   Pros: More readable and easier to maintain than traditional `for` loops. Eliminates the need for manual array indexing.
    *   Cons: Can be slower due to function call overhead. Not as efficient as `for` loops for very large arrays.
*   **`some` Loop**:
    *   Pros: Faster than `forEach` because it only executes when the predicate returns `true`, eliminating unnecessary iterations.
    *   Cons: More complex to use and less intuitive, especially for those unfamiliar with its behavior. May not be suitable for all scenarios.

**Library Usage**

There is no library explicitly mentioned in the benchmark definition or test cases. However, some JavaScript features might be implicitly used:

*   **Array Methods**: `forEach`, `some`, and potentially other array methods like `filter`, `map`, and `reduce`.
*   **Arrow Functions**: Used in the callback functions within `forEach` and `some`.

**Special JS Features**

There are no special JavaScript features or syntax explicitly mentioned or used in this benchmark. However, if we consider implicit usage:

*   **Arrow Functions**: As mentioned earlier, arrow functions are used within the loop callbacks.

**Other Alternatives**

For this specific use case, alternative approaches might include:

*   **`while` Loop**: A `while` loop can be used instead of a traditional `for` loop. It's more flexible but requires manual incrementing of the loop variable.
*   **`for...of` Loop**: The `for...of` loop is another alternative to traditional `for` loops. It's similar to `forEach` in terms of readability and avoids off-by-one errors.
*   **Custom Iterators**: If you need more control over iteration, you can create a custom iterator using the `Iterator` API.

The choice of approach ultimately depends on your specific requirements, performance constraints, and personal preference.

Latest run results:

Run details: (Test run date: 4 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:72.0) Gecko/20100101 Firefox/72.0

Browser/OS: Firefox 72 on Mac OS X 10.15

View result in a separate tab

Test name	Executions per second
for	2148271.5 Ops/sec
foreach	9247703.0 Ops/sec
some	8558061.0 Ops/sec

Related benchmarks:

for vs foreach vs some (version: 0)

Compare loop performance

Comparing performance of: for vs foreach vs some

Created: 8 years ago by: Guest

Jump to the latest result

for

foreach

some

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 26 days ago):