如何声明从另一个方法的返回类型引用的变量/方法类型

Question

One of my method returns a Class type. I wanna use this Class type as the parameter/return type of another method like:

class A {
  def aClass: Class[_] = {
    if (...){
      classOf[String]
    }else{
      classOf[Int]
    }
  }
   //Neither works
  def kClass : aClass = {
    //...
  }
  def kClass : Class[aClass] = {
    //...
  }
}

It complains Cannot resolve symbol aClass .

Can this type of metaprogramming be achieved in Scala at all?

Answer 1

you can define a type like this and can use that type. right now you are putting a def as a type and there is no type like aClass defined so it's giving you compile time error that aClass can't be resolved. I think that should work for you.

final type aClass = Class[_]

      class A {
        def aClass: Class[_] = {
          if (true){
            classOf[String]
          }else{
            classOf[Int]
          }
        }

        //should works
        def kClass: aClass = {
          ...
        }
        def kClass1: aClass = {
          ...
        }
      }