Classes (object orientation)

This lesson covers the basics of writing a class in Scala.

A class is defined as class Name(args), and the constructor arguments can be used directly as fields. Methods are defined with def.

The sample code defines class Animal(val name: String) with a speak() method that returns the sound it makes.

A common early stumble is just how brief the constructor is. Developers coming from Java tend to define one separately, but in Scala the () after the class name is the constructor.

In professional work, this concise class definition lets you express data and behaviour together in very little code.

📖 Reference code

class Animal(val name: String) {
  def speak(): String = {
    s"$name is making a sound."
  }
}

object Main extends App {
  val dog = new Animal("Rex")
  println(dog.speak())
}

✍️ Your code

Type your code, then press "Run"

🧪 This site can't compile or run Scala directly, so it checks on the spot whether what you typed matches the reference code (scoring happens entirely in your browser — nothing is sent anywhere).