Benchmark: Reduce(with spread) vs Map

Script Preparation code:

var a = [];
for (let i = 0; i < 1000; i++) {
    a.push(Number(i) / 1000);
}
var mapping = x => x * 5.5;
var reducing = (acc, x) => {
    return [...acc, x * 5.5]
}

Tests:

Reduce
a.reduce(reducing, []);
Map
a.map(mapping)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Reduce
Map

Fastest: N/A

Slowest: N/A

Latest run results:

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

LLMs can make mistakes. Check important info.

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**Benchmark Overview**

The provided benchmark compares two approaches: using `map()` and using `reduce()`. Both methods are used to perform an operation on each element of an array. In this case, the operation is multiplying each number by a constant factor (5.5) and then adding it to an accumulator.

**Options Compared**

The two options being compared are:

1. **Map**: The `map()` method applies a specified function to every element in an array, returning a new array with the results.
2. **Reduce**: The `reduce()` method applies a function to each element of an array, accumulating a result.

**Pros and Cons**

*   **Map**
    *   Pros:
        *   Can be more readable and easier to understand for simple operations.
        *   Returns a new array with the results, which can be useful for further processing.
    *   Cons:
        *   Creates a new array in memory, which can lead to increased memory usage for large datasets.
*   **Reduce**
    *   Pros:
        *   Can be more efficient than `map()` as it only iterates over the elements once.
        *   Returns the accumulated result directly, without creating an additional array.

**Library and Special JS Feature**

There is no specific library being used in this benchmark. However, note that some older browsers may not support modern JavaScript features like `const`, `let`, or arrow functions (e.g., `x => x * 5.5`).

**Other Considerations**

*   **Array Size**: The array size (1000) is relatively small, which might affect the results of the benchmark.
*   **Browser and Device Platform**: The benchmark uses a specific browser version (Chrome 108) and device platform (Desktop Windows), so results may vary with other browsers and platforms.

**Alternatives**

If you're looking for alternative approaches to `map()` or `reduce()`, consider:

1.  **forEach()**: A traditional loop-based method that can be more efficient but requires manual indexing.
2.  **Iterators**: JavaScript's built-in iterators provide a way to iterate over arrays without creating new arrays.
3.  **Closures**: Using closures can create an efficient and reusable function for array operations.

These alternatives might offer better performance or readability depending on your specific use case, but they often come with trade-offs in terms of complexity or code size.

Related benchmarks:

Reduce(with spread) vs Map (version: 0)

Comparing performance of: Reduce vs Map

Created: 3 years ago by: Guest

Jump to the latest result

Reduce

Map

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

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