Benchmark: Object.fromEntries vs create temp object

Script Preparation code:

var array = Array.from(Array(10000).keys())

Tests:

Object.fromEntries
Object.fromEntries(array.map(value => [value, value]));
creating temporary objects
const data = {} array.forEach(value => data[value] = value);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Object.fromEntries
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 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/133.0.0.0 Safari/537.36

Browser/OS: Chrome 133 on Linux

View result in a separate tab

Test name	Executions per second
Object.fromEntries	1714.0 Ops/sec
creating temporary objects	14253.9 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 provided benchmark and explain what's being tested.

**Benchmark Overview**

The benchmark is comparing two approaches to create objects in JavaScript:

1. Using `Object.fromEntries` with an array of key-value pairs.
2. Creating a temporary object using an array's `forEach` method.

**Options Being Compared**

* `Object.fromEntries`: A built-in JavaScript method introduced in ECMAScript 2015 (ES6), which creates a new object from an iterable of key-value pairs.
* Creating a temporary object: This approach involves iterating over the array and assigning each value to a property on a newly created object.

**Pros and Cons**

* `Object.fromEntries`:
	+ Pros:
		- Concise and expressive syntax
		- Creates a new object without modifying an existing one
	+ Cons:
		- May be slower due to the overhead of creating a new object and iterating over the array
* Creating a temporary object:
	+ Pros:
		- May be faster since it avoids the overhead of creating a new object
	+ Cons:
		- More verbose syntax compared to `Object.fromEntries`
		- Requires more memory allocation and garbage collection

**Library Usage**

There is no explicit library usage in this benchmark. However, the `Array.from()` method is used to create an array from another iterable (in this case, an array of numbers).

**Special JS Features/Syntax**

* There are no special JavaScript features or syntax specific to this benchmark.

**Other Considerations**

The benchmark results are based on the Chrome 90 browser running on a desktop Windows platform. The test is designed to measure the execution speed of each approach, with multiple executions per second reported.

**Alternative Approaches**

Other approaches to create objects in JavaScript could include:

* Using `Array.prototype.reduce()` or other aggregation methods
* Creating an object using a loop and assigning properties manually
* Using a library like Lodash or Underscore.js for object creation

However, these alternatives are not being tested in this specific benchmark.

Related benchmarks:

Object.fromEntries vs create temp object (version: 0)

Comparing performance of: Object.fromEntries vs creating temporary objects

Created: 4 years ago by: Guest

Jump to the latest result

Object.fromEntries

creating temporary objects

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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