Scala classes can also extend and mix in multiple traits. You can use them just like a Java interface, and you can also use them like abstract classes that have real methods. You cannot extend multiple abstract classes but you can extend multiple traits. Scala traits are a great feature of the language. In Scala, a trait is almost like an abstract class except that it does not have a constructor. Traits are similar to interfaces in Java and are created using trait keyword. Scala classes can also extend and mix in multiple traits. Difference between Traits and Abstract Classes in Scala. As you’ll see in the following lessons, you can use them just like a Java interface, and you can also use them like abstract classes that have real methods. You can define methods in traits as you can in abstract classes. Scala traits are a great feature of the language. Internal Memory: 8Gb Scala Trait having abstract and non-abstract methods: Implementations of traits are compile into Java interfaces with corresponding implementation classes that hold the methods implemented in the traits. A variable declared with val or var but not initialized is considere abstract. Consider a Trait Reader which provides a abstract read method. Lets have a look at Trait being used as a Interface in Java. also read: Primary and Auxiliary Constructors in Scala Traits in Scala Java HelloWorld vs Scala HelloWorld Traits like Interfaces in Java. You can create traits that have all abstract methods or some abstract methods and some non-abstract methods.Īny variable declare using the val or var keyword in a trait gets implement internally in the class that implements the trait. And one such construct in Scala are Traits. If a trait contains method implementation, then the class which extends this trait need not implement the method which already implemented in a trait. Scala trait is a collection of abstract and non-abstract methods. In Scala, we are allowed to implement the method (only abstract methods) in traits. Scala trait is like an interface with partial implementation.