将数组作为案例类的单独参数传递

Question

I have a Scala case class with the following declaration:

case class Student(name: String, firstCourse: String, secondCourse: String, thirdCourse: String, fourthCourse: String, fifthCourse: String, sixthCourse: String, seventhCourse: String, eighthCourse: String)

Before I create a new Student object, I have a variable holding the value for name and an array holding the values for all 8 courses. Is there a way to pass this array to the Student constructor? I want it to look cleaner than:

val firstStudent = Student(name, courses(0), courses(1), courses(2), courses(3), courses(4), courses(5), courses(6), courses(7))

Answer 1

You can always write your own factory methods on the Student companion object:

case class Student(
  name: String, firstCourse: String, secondCourse: String,
  thirdCourse: String, fourthCourse: String, 
  fifthCourse: String, sixthCourse: String, 
  seventhCourse: String, eighthCourse: String
)

object Student {
  def apply(name: String, cs: Array[String]): Student = {
    Student(name, cs(0), cs(1), cs(2), cs(3), cs(4), cs(5), cs(6), cs(7))
  }
}

and then just call it like this:

val courses: Array[String] = ...
val student = Student("Bob Foobar", courses)

Why you need a case class with 8 similar fields is another question. Something with automatic mappings to a database of some kind?