Can you explain the main principles of object-oriented programming?

The main principles of object-oriented programming (OOP) include:

• Encapsulation — combining data and methods that operate on that data into a single object, as well as hiding internal implementation details from the outside world.
• Inheritance — the ability to create new classes based on existing ones, inheriting their properties and methods, which promotes code reuse.
• Polymorphism — the ability of objects of different classes to respond to the same messages (method calls) in different ways, ensuring flexibility and extensibility.
• Abstraction — highlighting the essential characteristics of an object while hiding implementation details, simplifying interaction with the object.

In JavaScript (Node.js), OOP is implemented through prototypes and classes. For example:

class Animal {
  constructor(name) {
    this.name = name;
  }
  speak() {
    console.log(`${this.name} makes a sound.`);
  }
}

class Dog extends Animal {
  speak() {
    console.log(`${this.name} barks.`);
  }
}

const dog = new Dog('Sharik');
dog.speak(); // Sharik barks.

Here, Dog inherits from Animal, overrides the speak method (polymorphism), and data and methods are encapsulated within classes.