Javascript Programming Tutorials, Guides & Best Practices

The extends keyword is used to create a subclass (child class) that inherits from another class (parent class).

class Animal {
  constructor(type, name) {
    this.type = type;
    this.name = name;
  }

  speak() {
    console.log(`${this.name} makes a noise.`);
  }
}

class Dog extends Animal {
  constructor(name, breed) {
    super('Dog', name);
    this.breed = breed;
  }

  speak() {
    console.log(`${this.name} barks.`);
  }
}

const dog = new Dog('Buddy', 'Golden Retriever');
dog.speak(); // Output: Buddy barks.