Scala вопросы и ответы для интервью
Вопрос 11. Explain the 'self' type in Scala.
The 'self' type is a way to declare the type of 'this' within a class or trait. It is often used in situations where the type of 'this' needs to be specified explicitly.
Вопрос 12. What is the 'type' keyword used for in Scala?
The 'type' keyword is used to define type aliases in Scala. It allows developers to create alternative names for existing types, improving code readability and maintainability.
Вопрос 13. Explain the concept of covariance and contravariance in Scala.
Covariance allows a type parameter to vary in the same direction as the container type, while contravariance allows it to vary in the opposite direction. They are denoted by + and - symbols, respectively.
Вопрос 14. What is the purpose of the 'Seq' trait in Scala?
'Seq' is a trait in Scala that represents sequences—ordered collections of elements. It is a subtrait of 'Iterable' and provides methods for indexing, length, and more.
Вопрос 15. Explain the 'copy' method in case classes.
The 'copy' method is automatically generated for case classes in Scala. It allows you to create a new instance of the case class with some fields modified, providing a convenient way to copy and update objects.
Самое полезное по оценкам пользователей:
- What is a higher-order function?
- Explain the 'yield' keyword in Scala.
- Explain the difference between val and var in Scala.
- What is the purpose of the 'case' keyword in Scala?
- What are the advantages of using the 'Option' type over null in Scala?