Benchmark: Class VS Function Benchmark Test

Script Preparation code:

var arr = [];

Tests:

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

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
function declaration
function expression
class

Fastest: N/A

Slowest: N/A

Latest run results:

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

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Let's break down the provided JSON and explain what's being tested, compared, and considered in each test case.

**Benchmark Overview**

The benchmark tests three different approaches to adding items to an array:

1. **Function Declaration**: A function declared using the `function` keyword.
2. **Function Expression**: An anonymous function declared using the `function` keyword without a name.
3. **Class**: An object created using a class definition.

**Test Case Analysis**

### Function Declaration

* The benchmark code is: `var arr = []; for (let i = 1; i < 10000; i++) { functionDeclaration(i); }`
* This test case compares the performance of calling a function declared with the `function` keyword.
* Pros:
	+ Easy to read and write.
	+ Allows for easy modification of the function body.
* Cons:
	+ May not be the most efficient way to declare small functions.

### Function Expression

* The benchmark code is: `var functionExpression = function(item) { arr.push(item); }; for (let i = 1; i < 10000; i++) { functionExpression(i); }`
* This test case compares the performance of calling a function declared as an expression without a name.
* Pros:
	+ Compact and efficient way to declare small functions.
	+ Can be useful in functional programming paradigms.
* Cons:
	+ May not be immediately clear to readers.
	+ Can make it harder to debug.

### Class

* The benchmark code is: `class Test { constructor() { this.arr = []; } addItem(item){ this.arr.push(item); } }; const test = new Test(); for (let i = 1; i < 10000; i++) { test.addItem(i); }`
* This test case compares the performance of calling a method on an object created using a class definition.
* Pros:
	+ Encapsulates data and behavior into a single unit.
	+ Can be used to create more complex objects with inheritance.
* Cons:
	+ May require additional setup and configuration.
	+ Can add overhead due to object creation.

**Library Usage**

In the benchmark, the `arr` variable is not explicitly defined as an array. However, it's clear that it's intended to be one because elements are being pushed onto it using the `push()` method. In JavaScript, when a variable is assigned a value but is not explicitly declared as an array or object, it defaults to a primitive type (e.g., number, string). To create an array, you need to use the `Array` constructor or the spread operator (`[]`). The benchmark code uses a variable declaration instead, which creates an empty array.

**Special JS Features**

None of the test cases explicitly use any special JavaScript features such as async/await, promises, closures, or modern ECMAScript syntax like `const`, `let`, or `class` declarations. However, it's worth noting that some browsers may have enabled certain experimental features by default, which could affect benchmark results.

**Alternatives**

Other alternatives for adding items to an array include:

1. **Using the spread operator**: `arr.push(...items)`
2. **Using the `Array.prototype.unshift()` method**: `arr.unshift(items)`
3. **Using a custom implementation**: Creating a custom array-like data structure or using a library like Lodash.

Keep in mind that each approach has its trade-offs and may be more suitable for specific use cases. The benchmark results will likely vary depending on the language runtime, hardware, and other factors.

Related benchmarks:

Class VS Function Benchmark Test (version: 0)

Comparing performance of: function declaration vs function expression vs class

Created: 3 years ago by: Guest

Jump to the latest result

function declaration

function expression

class

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):