Scala实践8

scala> trait PhiloSophical {
     |   def philoSophize(): Unit ={
     |     println("I consum memory,therefore I am")
     |   }
     | }
defined trait PhiloSophical

scala> class Frog extends PhiloSophical{
     |    override def toString="green"
     | }
defined class Frog

scala> val frog=new Frog
frog: Frog = green

scala> frog.philoSophize()
I consum memory,therefore I am

scala> val phil:philoSophize=frog
<console>:12: error: not found: type philoSophize
       val phil:philoSophize=frog
                ^

scala> val phil:PhiloSophical=frog
phil: PhiloSophical = green

scala> phil.philoSophize
I consum memory,therefore I am