Benchmark: Sorting array into 2 arrays with reduce vs forEach

Script Preparation code:

var timeSlots = [
  {start_date: "2020-10-15T19:14:46.599Z", end_date: "2020-10-15T19:14:46.599Z", id: 1},
  {start_date: "2020-10-15T19:14:46.599Z", end_date: "2020-10-15T19:14:46.599Z", id: 0},
  {start_date: "2020-10-15T19:14:46.599Z", end_date: "2020-10-15T19:14:46.599Z", id: 1},
  {start_date: "2020-10-15T19:14:46.599Z", end_date: "2020-10-15T19:14:46.599Z", id: 0},
  {start_date: "2020-10-15T19:14:46.599Z", end_date: "2020-10-15T19:14:46.599Z", id: 1},
  {start_date: "2020-10-15T19:14:46.599Z", end_date: "2020-10-15T19:14:46.599Z", id: 0},
  {start_date: "2020-10-15T19:14:46.599Z", end_date: "2020-10-15T19:14:46.599Z", id: 1},
  {start_date: "2020-10-15T19:14:46.599Z", end_date: "2020-10-15T19:14:46.599Z", id: 0},
  {start_date: "2020-10-15T19:14:46.599Z", end_date: "2020-10-15T19:14:46.599Z", id: 1},
  {start_date: "2020-10-15T19:14:46.599Z", end_date: "2020-10-15T19:14:46.599Z", id: 0},
  {start_date: "2020-10-15T19:14:46.599Z", end_date: "2020-10-15T19:14:46.599Z", id: 1},
  {start_date: "2020-10-15T19:14:46.599Z", end_date: "2020-10-15T19:14:46.599Z", id: 0},
  {start_date: "2020-10-15T19:14:46.599Z", end_date: "2020-10-15T19:14:46.599Z", id: 1},
  {start_date: "2020-10-15T19:14:46.599Z", end_date: "2020-10-15T19:14:46.599Z", id: 0},
  {start_date: "2020-10-15T19:14:46.599Z", end_date: "2020-10-15T19:14:46.599Z", id: 1},
];

Tests:

reduce
var [ newTimeSlots, editedTimeSlots ] = timeSlots.reduce( (splitSlots, slot ) => { var arrayIndex = slot.id > 0 ? 1 : 0; splitSlots[arrayIndex].push({...slot, meeting: 1}); return splitSlots; }, [[], []]);
forEach
var newTimeSlots = []; var editedTimeSlots = []; timeSlots.forEach(slot => { slot.id > 0 ? editedTimeSlots.push({...slot, meeting: 1}) : newTimeSlots.push({...slot, meeting: 1}); });

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
reduce
forEach

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 dive into the benchmark.

**What is being tested?**

The provided JSON represents a JavaScript microbenchmark that tests two approaches to sorting an array of objects with a specific structure. The test case compares the performance of using `reduce` vs `forEach` methods to split an array of time slots into two separate arrays, each containing only the time slots with an ID greater than 0.

**Options being compared**

The benchmark tests two options:

1. **Reduce**: Using the `reduce` method to split the array. This approach is often used for functional programming and can be more concise.
2. **ForEach**: Using the `forEach` method to iterate over the array and split it into two separate arrays.

**Pros and cons of each approach**

* **Reduce**:
	+ Pros: Can be more concise and expressive, especially when dealing with complex data structures.
	+ Cons: May have performance overhead due to the creation of a new accumulator object for each iteration.
* **ForEach**:
	+ Pros: Can be easier to understand and maintain, as it's a familiar loop construct.
	+ Cons: May require more code and be less concise than using `reduce`.

**Library usage**

There is no explicit library mentioned in the benchmark definition or test cases. However, it's worth noting that some JavaScript environments (e.g., browsers) may have built-in optimizations or caching for certain functions, which could impact the results.

**Special JS feature**

The benchmark uses a specific syntax for object destructuring and spreading (`{...slot, meeting: 1}`), which is supported by modern JavaScript engines. This syntax allows for concise creation of new objects with modified properties.

**Other alternatives**

If you wanted to test other approaches, here are some additional options:

* **Map**: Similar to `reduce`, but uses the `map` method instead.
* **Destructuring assignment with multiple loops**: Using multiple loops to assign values from each object to separate arrays.
* **Looping constructs**: Using traditional `for` loops or `while` loops to iterate over the array and split it into two arrays.

Keep in mind that these alternatives might not be as concise or expressive as using `reduce` or `forEach`, but can still provide interesting performance comparisons.

Related benchmarks:

Sorting array into 2 arrays with reduce vs forEach (version: 0)

When sorting an array, you can use reduce or forEach

Comparing performance of: reduce vs forEach

Created: 5 years ago by: Guest

Jump to the latest result

reduce

forEach

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):