Considering this trait 'Person' and this class 'PersonImpl':
trait Person { def name: String def surname: String def married: Boolean def married_=(state: Boolean): Unit override def toString(): String = name + " " + surname + " " + married } class PersonImpl(override val name: String, override val surname: String, override var married: Boolean) extends Person Using REPL (scala from command line, just open a terminal and type scala) I create the trait and the class. I have the following messages: -defined Trait Person -defined class PersonImpl
Then, still from the command line, I type:
- val p: Person = new PersonImpl1("mario", "rossi", false)
- println(p)
- p.married=true
- prinln(p)
I can clearly see that my person has been created and the var field married has been changed from false to true. Allright. Now I am repeating the same process just with another class and another trait:
trait Element { def x: Int def y: Int def width: Int def height: Int def x_:(i:Int):Unit def y_:(i:Int):Unit override def toString(): String = x + " " + y + " " + width + " " + height } class GameElement(override var x: Int,override var y: Int,override val width: Int,override val height: Int) extends Element As soon as I type the class into the command line I run into the error: 'variable x overrides nothing'
How can this be possible?
