Benchmark: function vs class 2

Script Preparation code:

var arr = [];

Tests:

function declaration
function functionDeclaration(item) { arr.push(item); } for (let i = 1; i < 10000; i++) { functionDeclaration(i); }
class
class Test { constructor(item) { this.item = item; } addItem(){ arr.push(this.item) } } for (let i = 1; i < 10000; i++) { new Test(i).addItem(); }
class 2
class Test { constructor(item) { arr.push(item); } } for (let i = 1; i < 10000; i++) { new Test(i); }
var function expression
var functionExpression = function(item) { arr.push(item); }; for (let i = 1; i < 10000; i++) { functionExpression(i); }
let function expression
let functionExpression = function(item) { arr.push(item); }; for (let i = 1; i < 10000; i++) { functionExpression(i); }
const function expression
const functionExpression = function(item) { arr.push(item); }; for (let i = 1; i < 10000; i++) { functionExpression(i); }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
function declaration
class
class 2
var function expression
let function expression
const function expression

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/89.0.4389.82 Safari/537.36

Browser/OS: Chrome 89 on Windows

View result in a separate tab

Test name	Executions per second
function declaration	277.6 Ops/sec
class	152.6 Ops/sec
class 2	231.8 Ops/sec
var function expression	294.9 Ops/sec
let function expression	332.7 Ops/sec
const function expression	286.3 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into the explanation of the provided benchmark.

**Benchmark Overview**

The benchmark measures the performance difference between various ways of creating and executing functions in JavaScript. The test cases compare four approaches:

1. **Function Declaration**: A traditional function declaration using the `function` keyword.
2. **Class**: Creating a class with a constructor and an instance method (in this case, `addItem`).
3. **Function Expression**: Creating a function expression using the `function` keyword without the `function` keyword (i.e., `var`, `let`, or `const`).
4. **Class 2**: A variant of the Class approach with a modified constructor that directly pushes the item to the array instead of assigning it to an instance property.

**Options Compared**

The benchmark compares the performance of each approach in executing the same code:

* For Function Declaration and Class, the test creates a function or class instance for each iteration of the loop (1-10,000).
* For Function Expression, the test creates a function expression for each iteration of the loop.
* For Class 2, the test creates an instance of the modified class for each iteration of the loop.

**Pros and Cons**

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

* **Function Declaration**: This is a traditional way of creating functions in JavaScript. Pros: easy to understand, well-established syntax. Cons: can lead to function scoping issues if not used carefully.
* **Class**: Creating classes provides a more object-oriented way of organizing code. Pros: encapsulation, inheritance, and polymorphism benefits. Cons: requires more boilerplate code and can be slower due to the overhead of creating objects.
* **Function Expression**: Function expressions are concise and flexible but lack some features of traditional functions (e.g., `this` context). Pros: concise syntax, flexible usage. Cons: may lead to confusion or errors if not used carefully.
* **Class 2**: This approach modifies the Class approach by directly pushing items to the array in the constructor. Pros: potentially faster due to reduced object creation. Cons: less intuitive and may lead to unexpected behavior.

**Library Usage**

None of the test cases use any external libraries. The focus is solely on comparing the performance of different JavaScript language constructs.

**Special JS Features or Syntax**

There are no special features or syntax used in this benchmark that would require specific knowledge to understand. However, it's worth noting that the `this` keyword and function scoping rules can be complex topics in JavaScript.

**Alternatives**

Other alternatives for measuring JavaScript performance include:

* V8 JavaScript Engine Microbenchmark (a similar benchmarking framework)
* JSPerf (a web-based benchmarking tool)
* Benchmark.js (a lightweight, modular benchmarking library)
* Node.js Performance Testing (using tools like `performance` module)

These alternatives can provide more comprehensive insights into JavaScript performance and may offer additional features or customization options.

Related benchmarks:

function vs class 2 (version: 0)

Comparing performance of: function declaration vs class vs class 2 vs var function expression vs let function expression vs const function expression

Created: 3 years ago by: Guest

Jump to the latest result

function declaration

class

class 2

var function expression

let function expression

const function expression

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):