How is polymorphism implemented in Node.js?

Polymorphism in Node.js is implemented through prototype inheritance and JavaScript's dynamic typing.

Main methods:

• Prototype inheritance: objects can inherit properties and methods from other objects, allowing behavior to be overridden.

• Constructor functions and classes (ES6+): you can create classes with methods that can be overridden in subclasses.

• Dynamic typing: functions can accept arguments of different types and behave differently depending on the type or data structure.

Example with classes and method overriding:

class Animal {
  speak() {
    console.log('Animal makes a sound');
  }
}

class Dog extends Animal {
  speak() {
    console.log('Dog barks');
  }
}

const animal = new Animal();
const dog = new Dog();
animal.speak(); // Animal makes a sound
dog.speak();    // Dog barks

Thus, polymorphism in Node.js is achieved through JavaScript's inheritance and method overriding capabilities.