Benchmark: forEach vs reduce vs map vs filter vs for --ali

Script Preparation code:

var arr = [];
for (var i = 0; i < 12345; i++) {
  arr[i] = i;
}

 var sumReduce = 0,
  sumFor = 0;

Tests:

reduce
sumReduce = arr.reduce((lastValue, item) => { return sumReduce += item; });
for
for (var j = 0,l=arr.length; j < l; j++) { sumFor += arr[j]; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
reduce
for

Fastest: N/A

Slowest: N/A

Latest run results:

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Autogenerated LLM Summary (model llama3.1:latest, generated one year ago):

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**Benchmark Overview**

The provided JSON represents a benchmark that compares the performance of different methods to perform an operation on an array: `forEach`, `reduce`, `map`, `filter`, and a traditional `for` loop. The test case, "sumReduce vs for", measures how efficiently each method can calculate the sum of all elements in the array.

**Test Cases**

There are two individual test cases:

1. **"reduce"**: This test uses the `Array.prototype.reduce()` method to calculate the sum of all elements in the array.
2. **"for"**: This test employs a traditional `for` loop to achieve the same result.

**JavaScript Features and Libraries**

In this benchmark, there are no special JavaScript features or libraries used beyond the standard methods provided by the Array prototype (`reduce`, `forEach`, etc.).

**Options Compared**

The two options being compared in this benchmark are:

1. **`Array.prototype.reduce()`**: This method takes a callback function as an argument, which is called for each element in the array. The accumulator (initial value) and the current element are passed to this callback function.
2. **Traditional `for` loop**: A classic looping construct used to iterate over elements in an array.

**Pros/Cons of Different Approaches**

Here's a brief comparison:

*   **`reduce()`**:
    *   Pros: Can be more concise and elegant code, especially when reducing arrays.
    *   Cons: May have performance overhead due to the callback function invocation.
*   **Traditional `for` loop**:
    *   Pros: Generally faster than callbacks, as it avoids the overhead of function calls.
    *   Cons: Can lead to less readable code and is often more verbose.

**Other Alternatives**

Additional methods that can be used to calculate the sum of an array include:

*   **`forEach()`**: While primarily intended for side-effecting operations (e.g., logging), it can also be used with a callback function to sum up elements.
*   **`map()`**: Although not typically used for summing arrays, `map()` could theoretically be employed in combination with another method (like `reduce()`) to achieve the desired result.

**Library and Purpose**

No external libraries are involved in this benchmark. The test cases rely solely on standard JavaScript methods and built-in functionality.

In conclusion, this benchmark provides a simple yet effective comparison of different approaches for calculating the sum of an array: using `Array.prototype.reduce()` versus a traditional `for` loop.

Related benchmarks:

forEach vs reduce vs map vs filter vs for --ali (version: 0)

Comparing performance of: reduce vs for

Created: 5 years ago by: Registered User

Jump to the latest result

reduce

for

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

Autogenerated LLM Summary (model llama3.1:latest, generated one year ago):