Question

我想根据scala

中的参数过滤列表

   case class Student(
   name:String,
   age:Int,
   subjects:List[Subject]
  )

  case class Subject(name:String,id:Int)

  val sub1=Subject("maths",101)
  val sub2=Subject("science",102)
  val sub3=Subject("english",103)
  val s1=Student("abc",20,List(sub1,sub2))
  val s2=Student("def",30,List(sub3,sub1))
  val s3=Student("XYZ",40,List(sub3,sub2))

  val sList=List(s1,s2)

 def findSubjectId(sList: List[Student], subject:String) {

 sList.map(student => student.copy(subjects =
    student.subjects.filter(_.name == subject)))
}

参数1 - 主题
参数2 - 年龄20 OR 30

结果 - 应该是可选的

Answer 1

你可以试试这个：

 sList
   .map(student => student.copy(
     subjects = student.subjects
       .filter(_.name == subject)))
   .filter(student => student.age == 20 || student.age == 30)

根据两个参数过滤列表

1 个答案: