Benchmark: new empty object vs constant vs frozen constant

Script Preparation code:

var empty={};
var frozen=Object.freeze({});
var fnNew=()=>({});
var fnConstant=()=>empty;
var fnFrozen=()=>frozen;

Tests:

empty
const arr=new Array(500).fill().map(()=>({}));
constant
const arr=new Array(500).fill().map(()=>empty);
frozen
const arr=new Array(500).fill().map(()=>frozen);
fn new
const arr=new Array(500).fill().map(fnNew);
fn constant
const arr=new Array(500).fill().map(fnConstant);
fn frozdn
const arr=new Array(500).fill().map(fnFrozen);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
empty
constant
frozen
fn new
fn constant
fn frozdn

Fastest: N/A

Slowest: N/A

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

LLMs can make mistakes. Check important info.

Measuring JavaScript performance is an essential task for any developer, especially when comparing different approaches to coding. Let's break down the provided benchmark and explain what's being tested.

**Benchmark Test Cases**

The test cases are designed to compare the performance of creating objects using different methods:

1. `empty`: Creating an empty object using the syntax `var empty = {};`.
2. `constant`: Creating a constant object using the syntax `const arr = new Array(500).fill().map(() => empty);`. This method creates an array, fills it with a function that returns an empty object, and maps each element to create another empty object.
3. `frozen`: Creating a frozen object using the syntax `var frozen = Object.freeze({});`.
4. `fnNew`: Invoking a function (not shown in the code) with an arrow function as its argument: `const arr = new Array(500).fill().map(() => fnNew());`. This method creates an array, fills it with a function that invokes another function (`fnNew`), and maps each element to create a new instance of the invoked function.
5. `fnConstant`: Invoking a constant object (created using the `constant` approach) as its argument: `const arr = new Array(500).fill().map(() => frozen);`. This method creates an array, fills it with a function that returns a frozen object, and maps each element to create another instance of the frozen object.
6. `fnFrozen`: Invoking a constant frozen object (created using the `frozen` approach) as its argument: `const arr = new Array(500).fill().map(() => fnFrozen());`. This method creates an array, fills it with a function that invokes another function (`fnFrozen`), and maps each element to create a new instance of the invoked frozen object.

**Options Compared**

The benchmark compares six different approaches:

* Creating an empty object using `var empty = {};`.
* Creating a constant object using `const arr = new Array(500).fill().map(() => empty);`.
* Creating a frozen object using `Object.freeze({});`.
* Invoking a function with an arrow function as its argument (`fnNew`).
* Invoking a constant object as its argument (`fnConstant`).
* Invoking a function that invokes another function (`fnFrozen`).

**Pros and Cons**

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

1. `empty`: Creates an empty object using a simple syntax. Pros: Simple, fast initialization time. Cons: May lead to unexpected behavior if not used carefully.
2. `constant`: Creates a constant object by mapping over an array of functions that return the same empty object. Pros: Constant object creation can be faster than creating a new object each time. Cons: Can create unnecessary objects in memory.
3. `frozen`: Creates a frozen object using `Object.freeze({});`. Pros: Ensures immutability and prevents modifications to the object. Cons: May incur additional overhead due to the freezing process.
4. `fnNew`: Invokes a function with an arrow function as its argument. Pros: Encapsulates creation logic in a reusable function. Cons: May lead to performance overhead due to function invocation.
5. `fnConstant`: Invokes a constant object as its argument. Pros: Reuses the same frozen object for all elements. Cons: May not be suitable for objects that require frequent updates or modifications.
6. `fnFrozen`: Invokes a function that invokes another function (`fnFrozen`). Pros: Encapsulates creation logic in a reusable function, similar to `fnNew`. Cons: May lead to performance overhead due to function invocation.

**Other Considerations**

* **Memory usage**: Creating large arrays of objects can lead to significant memory consumption. The benchmark's focus on creating an empty object, constant object, and frozen object allows for a comparison of memory usage.
* **Performance**: The benchmark measures the number of executions per second (ExecutionsPerSecond) for each test case. This value indicates how many times the code executes in one second.
* **Device platform**: The benchmark results show that the Mobile Safari 17 browser on an iPhone performs better than expected for some test cases, indicating potential optimization opportunities.

**Alternatives**

Other approaches could be explored to optimize object creation:

1. Using `const` keyword consistently: Instead of using `var`, consider using `const` keywords throughout to ensure immutability and prevent unnecessary reassignments.
2. Using libraries like Lodash or Immutable.js: These libraries provide optimized functions for creating immutable objects, which can lead to better performance and reduced memory usage.
3. Optimizing function invocations: Consider minimizing the number of function invocations using memoization, caching, or other optimization techniques.

By understanding these considerations and exploring alternative approaches, developers can optimize object creation in their codebases for improved performance and maintainability.

Latest run results:

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

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 17_5_1 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/17.5 Mobile/15E148 Safari/604.1

Browser/OS: Mobile Safari 17 on iOS 17.5.1

View result in a separate tab

Test name	Executions per second
empty	136276.9 Ops/sec
constant	51202.5 Ops/sec
frozen	47927.4 Ops/sec
fn new	138993.4 Ops/sec
fn constant	46238.8 Ops/sec
fn frozdn	44595.8 Ops/sec

Related benchmarks:

new empty object vs constant vs frozen constant (version: 0)

Comparing performance of: empty vs constant vs frozen vs fn new vs fn constant vs fn frozdn

Created: 3 months ago by: Guest

Jump to the latest result

empty

constant

frozen

fn new

fn constant

fn frozdn

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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