Polymorphism is something every developer who has done some object-oriented programming knows about.
Note
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.
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 a bottle." }
Let's now have a shopping basket of items and call pack
for each of them:
object SubtypePolymorphismExample { def main(args: Array[String]): Unit = { val shoppingBasket: List[Item] = List( new Fruit, new Drink ...