Benchmark: Reduce vs Object.groupBy

Script Preparation code:

var max2 = 100000;

var data = [];
for (var i = 0; i <= max2; i++) { data.push({ id: i }); }

Tests:

New native groupBy
Object.groupBy(data, ({ id }) => id)
Old native reduce
data.reduce((acc, item) => { acc[item.id] = item; return acc; }, {})

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
New native groupBy
Old native reduce

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 8 months ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:142.0) Gecko/20100101 Firefox/142.0

Browser/OS: Firefox 142 on Mac OS X 10.15

View result in a separate tab

Test name	Executions per second
New native groupBy	181.4 Ops/sec
Old native reduce	655.9 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the benchmark and explain what's being tested.

**Benchmark Definition**

The benchmark is testing two different approaches to achieve the same result: reducing an array of objects to a grouped object using either the `Object.groupBy` method (new native) or the `reduce` method (old native).

**Test Cases**

There are two test cases:

1. **New native groupBy**: This test case uses the new native `Object.groupBy` method to group the data array by the `id` property of each object.
2. **Old native reduce**: This test case uses the old native `reduce` method to achieve the same result as `Object.groupBy`.

**Options Compared**

The two approaches are compared in terms of performance, which is measured by the number of executions per second.

**Pros and Cons**

* **Object.groupBy (New Native)**:
	+ Pros: This approach is likely to be faster because it's a native method optimized for performance.
	+ Cons: It may not work in older browsers or environments that don't support this feature.
* **Reduce (Old Native)**:
	+ Pros: This approach is widely supported by most browsers and environments, making it a safe choice.
	+ Cons: It might be slower than `Object.groupBy` due to the overhead of looping through each element.

**Library and Purpose**

There is no library mentioned in this benchmark. However, the use of `Object.groupBy` suggests that the test is targeting modern browsers or environments that support this feature.

**Special JS Feature or Syntax**

No special JavaScript features or syntax are used in these test cases. They're relatively simple and straightforward.

**Other Considerations**

* The test data is created by pushing 100,000 objects onto an array, with each object having a unique `id` property.
* The benchmark uses Chrome 124 as the target browser, which suggests that the test is optimized for this specific version.
* The test only runs on desktop platforms, which might limit its relevance to mobile or other device types.

**Alternatives**

If you were to create a similar benchmark, you could consider adding additional test cases, such as:

* Using a different data structure, like an array of arrays
* Adding more complex data structures, like nested objects
* Testing the performance of these methods in different browsers or environments

Keep in mind that the specific approach and data used will impact the results of your benchmark.

Related benchmarks:

Reduce vs Object.groupBy (version: 0)

Testing the new native method

Comparing performance of: New native groupBy vs Old native reduce

Created: 2 years ago by: Guest

Jump to the latest result

New native groupBy

Old native reduce

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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