Benchmark: object.assign vs new class extends

Tests:

extend and create
class Vehicle { constructor(name){ this.name = name; } } class Ev extends Vehicle { constructor(name, charge){ super(name); this.charge = charge; } } const car = new Ev("leaf",90);
object.assign
class Vehicle { constructor(name){ this.name = name; } } const car = Object.assign(new Vehicle("leaf"),{ charge: 90 })

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
extend and create
object.assign

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/130.0.0.0 Safari/537.36

Browser/OS: Chrome 130 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
extend and create	585189.0 Ops/sec
object.assign	1227020.1 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks!

**What is being tested?**

The provided JSON represents two individual test cases:

1. "object.assign vs new class extends":
	* This benchmark compares the performance of creating a class that extends another class (`new class extends`) with creating a new instance using `Object.assign()`.
2. The second set of test cases:
	* Each test case measures the performance of either creating an instance of a class by extending another class (`class Vehicle { ... }` and `class Ev extends Vehicle { ... }`) or using `Object.assign()` to create a new instance with initial values.

**Options compared:**

The benchmark compares two main approaches:

1. **Class inheritance**: Creating a new instance by inheriting from an existing class.
2. **Object assignment**: Using `Object.assign()` to create a new object with initial values.

**Pros and Cons of each approach:**

**Class Inheritance**

Pros:

* Encapsulates data and behavior within a single unit (the class).
* Can provide additional benefits like polymorphism, inheritance, and composition.
* Typically more readable and maintainable code.

Cons:

* May lead to over-engineering or excessive use of abstraction.
* Can introduce complexity when trying to debug or optimize the class hierarchy.

**Object Assignment**

Pros:

* Provides a lightweight and flexible way to create objects with initial values.
* Can be faster than class inheritance, especially for simple cases.

Cons:

* Lacks encapsulation and data hiding.
* May lead to tight coupling between classes if not used carefully.

**Other considerations:**

1. **Library usage**: In the provided benchmark code, no specific libraries are mentioned. However, in general, JavaScript frameworks like React or Angular might influence the choice of class inheritance vs object assignment.
2. **Special JS features**: The benchmark does not explicitly use special JavaScript features like ES6 classes, async/await, or Promises.

**Alternative approaches:**

1. **Prototypal inheritance**: Another way to achieve class-like behavior without using classes.
2. **Functional programming**: Using functions and function composition to create objects with initial values.
3. **Object creation libraries**: Specialized libraries like Lodash or Underscore.js provide optimized object creation methods.

For the specific benchmark, it's essential to consider the trade-offs between encapsulation, readability, maintainability, and performance when choosing between class inheritance and object assignment.

Related benchmarks:

object.assign vs new class extends (version: 0)

Performance difference of creating a class that extends P and creating a new instance of it vs doing object.assign(new P(), ...)

Comparing performance of: extend and create vs object.assign

Created: 4 years ago by: Guest

Jump to the latest result

extend and create

object.assign

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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