Trait : 101 : Example...

scala> //  Traits can be mixed-in with other Classes #257

scala> //   Advantage over Inheritance

scala> //      - Multiple Traits can be mixed-in #257

scala> //      - super.xxx() calls are dynamically bound rather than

scala> //         statically bound (Can be used to implement Stackable

scala> //         modifications #260)

scala> //  Limitation

scala> //    - Traits cannot have Class Parameter #260

scala>

scala> //////////////////////////////////////////////

scala> //   Create a Trait

scala> //////////////////////////////////////////////

scala> //Note here : math implicitly extends 'AnyRef'

scala> trait math {
     |   def score() = {
     |     println("Score is 80")
     |   }
     | }
defined trait math

scala>

scala> trait science {
     |   def mark() = {
     |     println("Score is 90")
     |   }
     | }
defined trait science

scala>

scala> class history
defined class history

scala>

scala> //////////////////////////////////////////////

scala> //  Example 1 : Understanding the Syntax

scala> //////////////////////////////////////////////

scala> class Subject extends history with math with science
defined class Subject

scala> val sub = new Subject
sub: Subject = Subject@2df9c215

scala> sub.score()
Score is 80

scala>

scala> //////////////////////////////////////////////

scala> //  Example 2 : Overriding a method

scala> //////////////////////////////////////////////

scala> class Subject extends history with math with science {
     |   override def score() {
     |     println("New score is 75")
     |   }
     | }
defined class Subject

scala> val sub = new Subject
sub: Subject = Subject@19304519

scala> sub.score()
New score is 75

scala>

scala> //////////////////////////////////////////////

scala> //  Example 3 : Traits cannot have Class

scala> //              Parameter

scala> //////////////////////////////////////////////

scala> trait AnotherTrait(no: Int)
<console>:1: error: traits or objects may not have parameters
       trait AnotherTrait(no: Int)
                         ^

PS : A trait mixed into a Class can be called as Mixins #269