Benchmark: javascript ruletz

Tests:

for loop
const items = Array.from({ length: 100000 }, (_, index) => index); for (let i = 0; i < items.length; i++) { const result = items[i] * 2; }
forEach
const items = Array.from({ length: 100000 }, (_, index) => index); items.forEach((item) => { const result = item * 2; });
map
const items = Array.from({ length: 100000 }, (_, index) => index); const results = items.map((item) => { return item * 2; });
reduce
const items = Array.from({ length: 100000 }, (_, index) => index); const results = items.reduce((accumulator, item) => { const result = item * 2; accumulator.push(result); return accumulator; }, []);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
for loop
forEach
map
reduce

Fastest: N/A

Slowest: N/A

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

LLMs can make mistakes. Check important info.

Measuring performance and understanding the trade-offs of different approaches is essential for optimizing code.

The provided JSON represents benchmarks for JavaScript microbenchmarks, focusing on four common methods: loops (`for`, `forEach`, and `reduce`), and array manipulation (`map`). Each test case includes a script preparation code snippet that sets up an array with 100,000 elements using `Array.from()` method.

**Options compared:**

1. **For Loop**: A traditional loop that iterates over the array using an index variable.
2. **ForEach Loop**: An iteration method that executes a callback function for each element in the array.
3. **Map Method**: Returns a new array with the results of applying a given function to every element in this array.
4. **Reduce Method**: Applies a function against an accumulator and each value in the array (from left to right) to reduce it to a single output value.

**Pros and Cons:**

*   **For Loop**:
    *   Pros: Simple, well-supported by most browsers, can be optimized using `for...of` loop with iterators.
    *   Cons: Less efficient than other methods since it doesn't utilize the array's native data structure optimizations.
*   **ForEach Loop**:
    *   Pros: Easy to read and maintain, works well for many use cases where you need to iterate over an array.
    *   Cons: Less efficient compared to `map` or `reduce`, since the callback function performs unnecessary work in each iteration.
*   **Map Method**:
    *   Pros: Produces a new array with optimized performance and memory usage, allowing for easy side effects handling. Suitable when you need an independent operation result set.
    *   Cons: Returns a new array, which may not be desirable in certain cases where the original data should remain unchanged or has additional context information associated with each item.
*   **Reduce Method**:
    *   Pros: Efficiently handles accumulating values, useful for complex transformations requiring multiple steps. Suitable when handling operations requiring multiple iterations over an array.
    *   Cons: May be harder to read and maintain due to its more abstract nature compared to other methods.

In general, the choice of which method to use depends on your specific requirements:

*   Use `for` loops when performance is not a concern but you need direct access to array elements' indices or want to handle side effects.
*   Utilize `forEach` loops for simple iterations where readability and simplicity are more important than raw performance.
*   Prefer the `map` method when you're creating an independent result set without altering the original data, ensuring memory usage efficiency.
*   Employ the `reduce` method when handling complex transformations involving multiple iterations over an array.

**Library and its purpose:**

None in this benchmark.

**Special JS feature or syntax:**

The provided JSON does not utilize any special JavaScript features beyond standard language constructs like loops (`for`, `forEach`), array manipulation methods (`map`, `reduce`) with the addition of the spread operator (`...`) within the `Array.from()` method, which is a part of ECMAScript 2015 (ES6).

**Alternatives:**

Alternative methods to these commonly used JavaScript iteration techniques include:

*   **Closures**: Can be used in place of loops for iterating over arrays by utilizing functions that capture and return values.
*   **Iterators**: Allow for more control when dealing with asynchronous data sources or needing direct access to array elements' indices, though still may require browser support where the latest JavaScript standard might not be supported.

While there are various iteration methods in JavaScript, `for` loops (`for`, `forEach`, and `reduce`) remain some of the most widely used due to their simplicity, readability, and broad compatibility with existing JavaScript codebases.

Latest run results:

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

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/114.0.0.0 Safari/537.36

Browser/OS: Chrome 114 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
for loop	358.4 Ops/sec
forEach	295.1 Ops/sec
map	285.6 Ops/sec
reduce	278.0 Ops/sec

Related benchmarks:

javascript ruletz (version: 0)

Comparing performance of: for loop vs forEach vs map vs reduce

Created: one year ago by: Guest

Jump to the latest result

for loop

forEach

map

reduce

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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