Edit Question - KnowledgeHub

Title Body

When I'm programming in Java (or a similar language), I often employ a simple version of the Strategy pattern, using interfaces and implementation classes, to provide runtime-selectable implementations of a particular concept in my code. As a very contrived example, I might want to have the general concept of an Animal that can make a noise in my Java code, and want to be able to select the type of animal at runtime. So I would write code along these lines: interface Animal { void makeNoise(); } class Cat extends Animal { void makeNoise() { System.out.println("Meow"); } } class Dog extends Animal { void makeNoise() { System.out.println("Woof"); } } class AnimalContainer { Animal myAnimal; AnimalContainer(String whichOne) { if (whichOne.equals("Cat")) myAnimal = new Cat(); else myAnimal = new Dog(); } void doAnimalStuff() { ... // Time for the animal to make a noise myAnimal.makeNoise(); ... } Simple enough. Recently, though, I've been working on a project in Scala and I want to do the same thing. It seems easy enough to do this using traits, with something like this: trait Animal { def makeNoise:Unit } class Cat extends Animal { override def makeNoise:Unit = println("Meow") } class AnimalContainer { val myAnimal:Animal = new Cat ... } However, this seems very Java-like and not very functional--not to mention that traits and interfaces aren't really the same thing. So I'm wondering if there's a more idiomatic way to implement the Strategy pattern--or something like it--in my Scala code so that I can select a concrete implementation of an abstract concept at runtime. Or is using traits the best way to achieve this?

Tags (comma-separated) Cancel