What is the difference between a trait and an abstract class in Scala?

What is the difference between a trait and an abstract class in Scala?

When it comes to Scala, traits and abstract classes are two powerful features that play a significant role in defining class hierarchies and code reuse. Understanding the differences between them is crucial for writing efficient and maintainable Scala code.

Trait in Scala:

A trait in Scala is similar to an interface in Java, as it defines a blueprint of methods and fields that a class can implement. Traits can also have concrete methods and fields alongside abstract ones.

Abstract Class in Scala:

An abstract class in Scala is a class that cannot be instantiated on its own and may contain both abstract and concrete methods. Subclasses can extend an abstract class and provide implementations for its abstract methods.

Differences:

• Multiple inheritance: Scala allows a class to inherit from multiple traits, but it can only extend one abstract class.
• Constructor parameters: Abstract classes can have constructor parameters, while traits cannot.
• Code reuse: Traits are often used for code reuse through mixin composition, while abstract classes are more suitable for building class hierarchies.

In conclusion, traits and abstract classes are essential components of Scala programming, each serving different purposes in class design and code organization.