Benchmark: 10k: Test Object.values vs array map for creating object array list

Script Preparation code:

var list = Array.from({
    length: 10000
}).map((_, idx) => idx);
var objects = Object.fromEntries(list.map((v, idx) => [idx, {
    index: idx,
    title: 'test'
}]))

Tests:

Object.values()
Object.values(objects)
Array.map()
list.map((idx) => { objects[idx] })

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Object.values()
Array.map()

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/126.0.0.0 Safari/537.36

Browser/OS: Chrome 126 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Object.values()	72024.7 Ops/sec
Array.map()	2768.6 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 designed to compare the performance of two approaches:

1. `Object.values(objects)`
2. `list.map((idx) => { objects[idx] })`

These approaches aim to create an array list from a large dataset (10000 elements). The test measures which approach performs better in terms of speed.

**Approach 1: Object.values(objects)**

This approach uses the `Object.values()` method, which returns an array of values of the properties of an object. In this case, `objects` is an object created from another array list using `Object.fromEntries()`. The idea is to extract all the property values (which are just the index and title) into a new array.

**Approach 2: Array.map((idx) => { objects[idx] })**

This approach uses the `Array.map()` method, which applies a function to each element of an array. In this case, the function takes an index as input and returns the corresponding property value from the `objects` array using object indexing (e.g., `objects[idx]`). The result is a new array with the same number of elements.

**Pros and Cons**

**Object.values(objects)**

Pros:

* Concise code
* No explicit looping required

Cons:

* May not be as efficient due to object lookup overhead
* Requires an existing object (which might not always be available)

**Array.map((idx) => { objects[idx] })**

Pros:

* More control over the iteration process
* Easier to modify or add functionality for each element

Cons:

* More verbose code
* Requires explicit looping and indexing

**Library Usage**

The `Object.fromEntries()` method is a modern JavaScript feature introduced in ECMAScript 2015 (ES6). It allows creating an object from an iterable array of key-value pairs. This library usage is not specific to any particular framework or library, but rather a standard JavaScript method.

**Special JS Feature/Syntax**

There are no special JavaScript features or syntaxes being tested in this benchmark. The code only uses standard JavaScript methods and data structures (arrays, objects).

**Other Alternatives**

If you're looking for alternative approaches to create an array list from another dataset:

1. **For...of loop**: `var list = Array.from({ length: 10000 }, (_, idx) => idx);`
2. **Array.prototype.forEach()**: `var list = [ ... ]; var objects = []; list.forEach((idx, i) => { objects.push({ index: idx, title: 'test' }); })`
3. **Destructuring assignment**: This approach is similar to using `Object.fromEntries()` but with a more concise syntax.

These alternatives may have different trade-offs in terms of performance, readability, and maintainability, depending on your specific use case.

Related benchmarks:

10k: Test Object.values vs array map for creating object array list (version: 0)

Comparing performance of: Object.values() vs Array.map()

Created: 5 years ago by: Guest

Jump to the latest result

Object.values()

Array.map()

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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