Object Oriented Design

• classes: How do you decide what a class is and what it is not?
• classes and objects
• instance variables
• constructor (no destructor
• methods: private/public
• inheritence: rarely is this the best solution
• composition and delegation: a better solution
• Polymorphism
• “Duck” typing.
  • Do you see how duck typing is an alternative/complement to inheritence?
  • Consider a method like #can_speak? in a gaming application

Reference

• Great book on OO Design: Practical OO Design in Ruby