Lesson 5 — Classes

Blueprints for objects

A class is a blueprint for making objects that share the same shape and behaviour. The constructor runs when you write new ClassName(...) and stores data on this (the new object). Functions written inside the class are methods — every object made from it can call them.

class Dog {
  constructor(name) { this.name = name; }
  bark() { return this.name + " says woof"; }
}
console.log(new Dog("Rex").bark()); // Rex says woof

Why it matters: classes appear in many libraries and in browser APIs, and they are a tidy way to keep data and the code that uses it together.