Benchmark: Object.fromEntries vs reduce round 2

Script Preparation code:

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

Tests:

Object.fromEntries
Object.fromEntries(data.map((key) => [key, 'x']));
Reduce (creating temporary objects)
data.reduce((acc, k) => ({ ...acc, [k]: 'x' }), {});

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

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

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/112.0.0.0 Safari/537.36

Browser/OS: Chrome 112 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Object.fromEntries	2030.1 Ops/sec
Reduce (creating temporary objects)	96.0 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 explain what's being tested.

**Benchmark Definition**

The benchmark is defined as an object with several properties:

* `Name`: The name of the benchmark, which in this case is "Object.fromEntries vs reduce round 2".
* `Description`: An empty string, indicating that there is no description for this benchmark.
* `Script Preparation Code` and `Html Preparation Code`: These are code snippets that are executed before running each test case. In this case, they both create an array of keys using `Array.from(Array(10000).keys())`.

**Individual Test Cases**

There are two test cases:

1. **Object.fromEntries**
The benchmark definition is: `Object.fromEntries(data.map((key) => [key, 'x']));`
This uses the `Object.fromEntries()` method to create an object from an array of key-value pairs.

2. **Reduce (creating temporary objects)**
The benchmark definition is: `data.reduce((acc, k) => ({\r\n  ...acc,\r\n  [k]: 'x'\r\n}), {});`
This uses the `Array.prototype.reduce()` method to create an object from an array of key-value pairs. The accumulator (`acc`) is an empty object that gets updated with new properties in each iteration.

**Options Compared**

These two test cases compare the performance of:

* **Object.fromEntries()**: A modern JavaScript method for creating objects from arrays of key-value pairs.
* **Reduce (creating temporary objects)**: An older method using `Array.prototype.reduce()` to create objects from arrays, which involves creating a temporary object in each iteration.

**Pros and Cons**

### Object.fromEntries()

Pros:

* **Concise and expressive**: The syntax is simple and easy to read.
* **Efficient**: It creates an object by copying the key-value pairs from the array, making it efficient for large datasets.

Cons:

* **Support**: Not all older browsers or environments support this method (it was introduced in ES6).
* **Security**: It's possible to create objects with arbitrary keys and values using `Object.fromEntries()`, which can lead to security issues if not used carefully.

### Reduce (creating temporary objects)

Pros:

* **Wide browser support**: This method has been around for a long time, so most browsers and environments support it.
* **No memory allocation overhead**: The accumulator is passed by reference, avoiding the need to allocate new memory in each iteration.

Cons:

* **Verbose syntax**: The code can be more cumbersome due to the need to use object literals and bracket notation.
* **Performance**: Creating temporary objects in each iteration can lead to performance issues for large datasets.

**Libraries and Special Features**

There is no library being used in this benchmark. However, if you're interested in using a specific library or function that's not part of the standard JavaScript syntax, it might be related to other features like:

* `Array.prototype.map()`: Used in both test cases to transform the data array.
* `Object.assign()` or `Object.create()`: Alternative methods for creating objects from arrays.

**Other Alternatives**

If you're looking for alternative approaches, consider:

* Using a library like Lodash or Ramda, which provide more concise and expressive functions for working with arrays and objects.
* Utilizing modern JavaScript features like `for...of` loops or `Array.prototype.forEach()` to iterate over the data array.

Keep in mind that these alternatives might come with trade-offs in terms of performance, browser support, or security.

Related benchmarks:

Object.fromEntries vs reduce round 2 (version: 0)

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

Created: one year ago by: Guest

Jump to the latest result

Object.fromEntries

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):