Beginning Scala 2nd Edition

1. Listing 3-21. Implementing case features in a class on its own
   
2. classStuff(val name: String,valage: Int) {
   
3. overridedeftoString = "Stuff("+name+","+age+")"
   
4. overridedefhashCode= name.hashCode+ age
   
5. overridedefequals(other: AnyRef)= othermatch {
   
6. case s: Stuff=> this.name== s.name &&this.age == s.age
   
7. case _ => false
   
8. }
   
9. }
   
10. objectStuff {
    
11. defapply(name: String, age: Int) = newStuff(name,age)
    
12. defunapply(s: Stuff)= Some((s.name, s.age))
    
13. }

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1. Listing 3-22. Using def in the value class
   
2. class SomeClass(val i: Int) extends AnyVal {
   
3. def twice() = i*2
   
4. }
   
5. Here SomeClass is a user-defined value class that wraps the Int parameter and encapsulates a twice
   
6. method. To invoke the twice method, create the instance of the SomeClass class as follows:
   
7. scala> val v = new SomeClass(9)
   
8. v: SomeClass = SomeClass@9
   
9. scala> v.twice()
   
10. res5: Int = 18

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