Polymorphism is something every developer who has done some object-oriented programming knows about.


Polymorphism helps us to write generic code that can be reused and applied to a variety of types.

It is important to know that there are different types of polymorphism out there, and we will be looking at them in this section.

Subtype polymorphism

This is the polymorphism every developer knows about, and it's related to overriding methods in concrete class implementations. Consider the following simple hierarchy:

abstract class Item { def pack: String } class Fruit extends Item { override def pack: String = "I'm a fruit and I'm packed in a bag." } class Drink extends Item { override def pack: String = "I'm a drink and I'm packed in ...

Get Scala Design Patterns now with O’Reilly online learning.

O’Reilly members experience live online training, plus books, videos, and digital content from 200+ publishers.