There are also variants of the mkString methods called addString which append the constructed string to a StringBuilder object

The mkString and addString methods are inherited from List’s supertrait Traversable, so they are applicable to all other collections, as well.

object List_StringBuilder extends App{

val lst=List("america","india")
  val buf = new StringBuilder
  println(lst addString (buf, "(", ";", ")"))
  //stringbuilder object

}

(america;india)