Scala trait

traitallows you to describe what a class should look like.

You can implement functions that can be overridden. You can describe functions that have to be overridden.

New terms:

• to inherit: the action of extending a class
• Child: the class that inherit from a trait
• Parent: the class that is inherited from

Several new keywords today:

• extends: is the keyword to be able to inherit from a class
• override: tell that this element has been overridden.
• final: tell that this cannot be overridden
• protected: similar toprivatebut allow the child class to see this element.privatewould not allow the child to see it.