11.16. Common MistakesΒΆ

  • Using inheritance (is a kind of) when you should use association (has a). A school has classes, it is not a type of class. A high school is a kind of school.
  • Using a type field instead of subclasses. If you ever find yourself creating conditionals based on the type of object use subclasses instead.
  • Copying code instead of creating a subclass or pulling out a common superclass. If you every find yourself copying object fields or methods try creating a subclass instead or pull out a common superclass.
Next Section - 11.17. More Practice