Benchmark: flatMap vs reduce test 2

Script Preparation code:

var values = []
for(i=0; i<1000; i++){ values.push(1) }

Tests:

flatMap
values.flatMap(x => [x, x])
reduce
values.reduce((acc, x) => { acc.push(x, x); return acc; }, [])

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
flatMap
reduce

Fastest: N/A

Slowest: N/A

Latest run results:

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

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Let's break down what is tested in the provided JSON benchmark.

**Benchmark Overview**

The benchmark compares the performance of two JavaScript methods: `Array.prototype.flatMap()` and `Array.prototype.reduce()`. The benchmark uses an array of 1000 elements, all initialized to 1. The purpose of this benchmark is to measure the execution speed difference between these two methods for a simple flattening operation.

**Options Compared**

The two options compared are:

1. **flatMap**: Uses `Array.prototype.flatMap()` to create a new flattened array from the original array.
2. **reduce**: Uses `Array.prototype.reduce()` to reduce the array into a single value (in this case, an array of the same length as the original array).

**Pros and Cons**

* **flatMap**:
	+ Pros: More concise and expressive syntax, can be more efficient in certain scenarios (e.g., when dealing with arrays that contain other arrays).
	+ Cons: May have performance overhead due to the creation of a new array.
* **reduce**:
	+ Pros: Can be more flexible and versatile than `flatMap`, allowing for more complex reduction operations.
	+ Cons: May require more memory allocation and copies, potentially leading to performance issues.

**Library**

In this benchmark, no specific library is mentioned. However, both methods (`flatMap` and `reduce`) are built-in functions in JavaScript.

**Special JS Feature or Syntax**

There's no special feature or syntax mentioned in the benchmark that requires explanation.

**Other Alternatives**

If you're looking for alternative approaches to flatten an array, some options include:

1. **Using a loop**: You can use a simple loop to iterate over the array and push each element into a new array.
2. **Using `Array.prototype.map()` and then concatenating`: `arr.map(x => [x, x]).flat()`
3. **Using a library like Lodash's `flattenDeep()`**: `_.flattenDeep([1, 2, [3, 4]])`

Keep in mind that these alternatives may have different performance characteristics compared to the built-in `flatMap` and `reduce` methods.

The benchmark result shows that Chrome 101 on a Mac OS X 10.15.7 system performs better with the `reduce` method than with `flatMap`. This could be due to various factors, such as the specific implementation of these methods in the browser or the current performance characteristics of JavaScript engines.

Related benchmarks:

flatMap vs reduce test 2 (version: 0)

Comparing performance of: flatMap vs reduce

Created: 3 years ago by: Guest

Jump to the latest result

flatMap

reduce

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):