Scala trait - Is there an equivalent of Java interface public static field?

问题

In Java:

public interface Foo {

  public static final int Bar = 0;
}

And in Scala, how can I create a trait Foo that has Bar, and I can access it as: Foo.Bar?

回答1:

You can create a companion object (to make it the equivalent of static) and define the variable there using the final val keywords (to make it the equivalent of a final constant):

trait Foo { }

object Foo { 
  final val Bar = 0
}

Lots more on this here

来源：https://stackoverflow.com/questions/8867316/scala-trait-is-there-an-equivalent-of-java-interface-public-static-field