Benchmark: Object.fromEntries vs reduce [corrected]

Script Preparation code:

var data = { ...Array.from(Array(10000).keys()) };

Tests:

Object.fromEntries
Object.fromEntries(Object.entries(data));
Reduce (reuse object)
Object.entries(data).reduce((acc, [k, v]) => { acc[k] = v.toString(); return acc; }, {});
Reduce (creating temporary objects)
Object.entries(data).reduce((acc, [k, v]) => ({ ...acc, [k]: v.toString() }), {});

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Object.fromEntries
Reduce (reuse object)
Reduce (creating temporary objects)

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 3 years ago)

User agent: Mozilla/5.0 (X11; Linux x86_64; rv:92.0) Gecko/20100101 Firefox/92.0

Browser/OS: Firefox 92 on Linux

View result in a separate tab

Test name	Executions per second
Object.fromEntries	836.6 Ops/sec
Reduce (reuse object)	537.5 Ops/sec
Reduce (creating temporary objects)	0.2 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and its test cases.

**Benchmark Definition**

The benchmark measures the performance of two different approaches to creating an object from key-value pairs:

1. `Object.fromEntries`
2. `Reduce` (with two variations:
	* Reusing an existing object
	* Creating temporary objects)

**Options Compared**

The three options being compared are:

1. `Object.fromEntries`: a built-in JavaScript method that creates an object from an array of key-value pairs.
2. Reusing an existing object in the `Reduce` approach: creating an object and reusing it throughout the iteration, as opposed to creating a new temporary object on each iteration.
3. Creating temporary objects in the `Reduce` approach: creating a new object on each iteration.

**Pros and Cons**

Here's a brief summary of the pros and cons of each approach:

1. `Object.fromEntries`:
	* Pros: concise, efficient, and easy to read.
	* Cons: not supported in older browsers or Node.js versions.
2. Reusing an existing object in `Reduce`:
	* Pros: can be more memory-efficient than creating temporary objects.
	* Cons: may lead to slower performance due to the overhead of reusing an object.
3. Creating temporary objects in `Reduce`:
	* Pros: avoids the potential performance hit of reusing an object.
	* Cons: may lead to higher memory usage and slower performance due to object creation.

**Library and Purpose**

The `Array.from()` method is a built-in JavaScript library that creates a new array from an iterable source. It's used in the first test case (`Object.fromEntries`) to create an array of key-value pairs, which is then passed to `Object.fromEntries` for construction.

**Special JS Feature or Syntax**

There are no special features or syntaxes mentioned in this benchmark.

**Other Considerations**

When writing benchmarks, it's essential to consider factors like:

* Garbage collection overhead
* Cache behavior
* Browser engine-specific optimizations

In this case, the `Object.fromEntries` method is likely optimized for modern browsers and Node.js versions. The `Reduce` approach may be slower due to its use of iteration and potential reusing of objects.

**Alternatives**

If you're interested in exploring alternative approaches, here are a few options:

* Using other methods like `Array.prototype.reduce()` or `Array.prototype.map()`
* Creating an object manually using the `for...in` loop or `Object.create()` method
* Using a third-party library or utility function

Keep in mind that these alternatives may not be as efficient or concise as the original approaches, and may require additional considerations when writing your benchmark.

Related benchmarks:

Object.fromEntries vs reduce [corrected] (version: 0)

Comparing performance of: Object.fromEntries vs Reduce (reuse object) vs Reduce (creating temporary objects)

Created: 3 years ago by: Guest

Jump to the latest result

Object.fromEntries

Reduce (reuse object)

Reduce (creating temporary objects)

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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