Scala 面接の質問と回答
質問 31. What is a companion object in Scala?
A companion object is an object with the same name as a class and is defined in the same file. It is used to contain static methods and properties related to the class.
質問 32. What is a trait in Scala?
A trait is a collection of abstract and concrete methods that can be mixed into classes to provide additional functionality. Unlike classes, a class can extend multiple traits.
質問 33. Explain lazy evaluation in Scala.
Lazy evaluation is a strategy where the evaluation of an expression is delayed until its value is actually needed. It can improve performance by avoiding unnecessary computations.
質問 34. What is the 'for' comprehension in Scala?
The 'for' comprehension is a syntactic sugar for combining sequences of 'map', 'flatMap', and 'filter' operations. It makes code more readable and expressive.
質問 35. How does Scala support concurrency?
Scala provides actor-based concurrency using the Akka library. Actors are lightweight, concurrent entities that communicate through message passing.
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