📘 Classes & Inheritance in JavaScript

ES6 introduced the class syntax in JavaScript, making it easier to create objects and implement inheritance using a cleaner, more familiar syntax (especially for developers coming from OOP languages like Java or C++).

🎓 Declaring a Class

class Person {
  constructor(name, age) {
    this.name = name;
    this.age = age;
  }

  greet() {
    console.log(`Hi, I'm ${this.name} and I'm ${this.age} years old.`);
  }
}

const alice = new Person("Alice", 30);
alice.greet();

📚 Inheritance with extends

class Student extends Person {
  constructor(name, age, subject) {
    super(name, age); // Call parent constructor
    this.subject = subject;
  }

  study() {
    console.log(`${this.name} is studying ${this.subject}.`);
  }
}

const bob = new Student("Bob", 22, "Mathematics");
bob.greet();
bob.study();

🔧 Method Overriding

Child classes can override parent methods:

class Teacher extends Person {
  greet() {
    console.log(`Hello students, I'm Professor ${this.name}.`);
  }
}

const prof = new Teacher("Smith", 45);
prof.greet(); // Overridden version

🚀 Using super() and super.method()

class Developer extends Person {
  greet() {
    super.greet(); // Call parent greet()
    console.log("I write code every day!");
  }
}

const dev = new Developer("Eve", 27);
dev.greet();

🧠 Summary

• class simplifies prototype-based inheritance.
• Use extends to inherit from another class.
• super() calls the parent constructor.
• Child classes can override parent methods.