Benchmark: reduce vs map + fromEntries (2)

Script Preparation code:

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

Tests:

reduce
data.reduce((acc, k, v) => { acc[k] = v.toString(); return acc; }, {});
map + fromEntries
Object.fromEntries(data.map((k, v) => ([k, v.toString()])));

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
reduce
map + fromEntries

Fastest: N/A

Slowest: N/A

Latest run results:

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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, compared, and their pros and cons.

**Benchmark Overview**

The test measures the performance of two approaches to achieve a similar result: reducing an array of numbers to a new object with numeric keys and string values using either the built-in `reduce()` method or a combination of `map()` and `Object.fromEntries()`. The benchmark is designed to compare these two approaches, which are both used for data transformation and manipulation.

**Options Compared**

The two options being compared are:

1. **`data.reduce((acc, k, v) => {\r\n  acc[k] = v.toString();\r\n  return acc;\r\n}, {})`**: This approach uses the `reduce()` method to iterate over the array and accumulate the results in a new object.
2. **`Object.fromEntries(data.map((k, v) => ([k, v.toString()])))`**: This approach uses the `map()` function to transform each element of the array into an array of key-value pairs, which are then passed to `Object.fromEntries()` to create a new object.

**Pros and Cons**

1. **`reduce()` Method**
	* Pros:
		+ More concise and expressive code.
		+ Can be more efficient since it avoids the creation of intermediate arrays.
	* Cons:
		+ May not be as readable or maintainable for complex transformations.
2. **`map()` + `Object.fromEntries()` Approach**
	* Pros:
		+ More explicit and easier to understand for complex transformations.
		+ Can be more efficient since it avoids the need for a reduce callback function.
	* Cons:
		+ Creates an intermediate array, which can lead to increased memory usage.

**Library: `Object.fromEntries()`**

`Object.fromEntries()` is a modern JavaScript method introduced in ES2020 that allows you to create an object from an iterable of key-value pairs. It's a concise and expressive way to perform data transformation and manipulation.

**Special JS Feature: Arrow Functions (=>)**

The benchmark uses arrow functions (=>) to define the callback function for the `reduce()` method. This is a modern JavaScript feature that allows you to write concise and expressive code by defining small, single-expression functions. Arrow functions are anonymous functions defined using the syntax `(parameters) => {code}`.

**Other Alternatives**

If you need to perform similar transformations, you might consider other approaches:

* Using `Array.prototype.reduce()` with a traditional function callback instead of an arrow function.
* Using `Array.prototype.forEach()` and then creating an object manually using a loop.
* Using a library like Lodash or Underscore.js, which provide alternative implementations of the `reduce()` method.

Keep in mind that the best approach depends on your specific use case, performance requirements, and personal coding style.

Related benchmarks:

reduce vs map + fromEntries (2) (version: 0)

Comparing performance of: reduce vs map + fromEntries

Created: 3 years ago by: Guest

Jump to the latest result

reduce

map + fromEntries

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):