Classes & Modules

Object Oriented Programming (OOP) allows us to create structured blueprints for our data.

Inheritance

Don't repeat yourself. If you have a Dog and a Cat, they are both Animals. We can use extends to share common logic.

class Animal {
  constructor(name) {
    this.name = name;
  }
  speak() {
    console.log(this.name + " makes a noise.");
  }
}

class Dog extends Animal {
  speak() {
    // Override the parent method
    console.log(this.name + " barks!");
  }
}

const d = new Dog("Rex");
d.speak(); // "Rex barks!"

Modules (Import/Export)

Before ES6 modules, we had to put everything in one giant file or rely on global variables. Modules act as Firewalls. Variables defined in a module stay in that module unless explicitly exported.