Scala trait - implement inside Main object

Question

I have a trait and trying to implement it in Main object. Is this possible and what is the best practice?

trait PrintThis {
  def nowPrint (thing:String)
}

object Main extends PrintThis {
  def main(args: Array[String]): Unit = {

    def nowPrint(thing:String): Unit = {
      println("subject" )
    }

    nowPrint("test")

  }
}

If that is not possible - is this a better approach (extend trait in another class and implement trait method inside another class and then extend that class in Main class and call the method)?

trait One {
  def show()
}

class Two extends One {
  def show() {println ("This is a show!") }
}

object Main extends Two {
  def main(args: Array[String]): Unit = {
    show()
  }
}

Or maybe is better instantiating that new class inside Main and not extending it?

object Main  {
  def main(args: Array[String]): Unit = {
    var pointer:Two = new Two
    pointer.show()
  }
}

pramesh · Accepted Answer · 2018-04-29 11:10:18Z

1

No this is not a good approach. Main function is meant to start running your application. Why would you need to extend any class from Main? If you want to use other classes, simply call their objects.

answered Apr 29, 2018 at 11:10

pramesh

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2 Comments

Joe Over a year ago

Thanks. Do you mind sharing (code) what is a good approach in simple example like this?

Joe Over a year ago

Adjusted questions with another approach that worked.. Please comment.

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