object Demo {

   def main(args: Array[String]) = {

      println ("Apply method : " + apply("Zara", "gmail.com"));

      println ("Unapply method : " + unapply("Zara@gmail.com"));

      println ("Unapply method : " + unapply("Zara Ali"));

   }

​

   // The injection method (optional)

   def apply(user: String, domain: String) = {

      user +"@"+ domain

   }

​

   // The extraction method (mandatory)

   def unapply(str: String): Option[(String, String)] = {

      val parts = str split "@"

​

      if (parts.length == 2){

         Some(parts(0), parts(1))

      } else {

         None

      }

   }

}