Scala 面试题与答案
问题 26. What is a higher-order function?
A higher-order function is a function that takes other functions as parameters or returns functions as results.
问题 27. Explain pattern matching in Scala.
Pattern matching is a powerful feature in Scala that allows you to match complex data structures, making code more concise and readable.
问题 28. What is the purpose of the 'apply' method in Scala?
The 'apply' method is a special method in Scala that is invoked when an object is called like a function. It is often used to create objects without using the 'new' keyword.
问题 29. What is the difference between 'map' and 'flatMap' in Scala?
'map' applies a function to each element of a collection and returns a new collection of the results, while 'flatMap' applies a function that returns a collection to each element and flattens the results into a single collection.
问题 30. Explain the concept of immutability in Scala.
Immutability means that once an object is created, its state cannot be changed. In Scala, 'val' and immutable collections are used to create immutable data structures.
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