Week 03: Polymorphism

• Overloading

  After this unit, students should

  • understand what is overloading.
  • understand how to create overloaded methods.

• Polymorphism

  After this unit, students should

  • understand polymorphism.
  • be aware of dynamic binding.
  • be aware of the equals method and the need to override it to customize the equality test.
  • understand when narrowing type conversion and type casting are allowed.

• Method Invocation

  After this unit, students should

  • understand the two-step process that Java uses to determine which method implementation will be executed when a method is invoked.
  • understand that Class Methods do not support dynamic binding.

• Liskov Substitution Principle

  After this unit, students should

  • understand the type of bugs that reckless developers can introduce when using inheritance and polymorphism.
  • understand the Liskov Substitution Principle and thus be aware that not all IS-A relationships should be modeled with inheritance.
  • know how to explicitly disallow inheritance (for a class) or disallow overriding (for a method) with the final keyword.

• Abstract Class

  After this unit, students should

  • be familiar with the concept of an abstract class.
  • know the use of the Java keyword abstract and the constraints that come with it.
  • understand the usefulness of defining and using an abstract class.
  • understand what makes a class concrete.

• Interface

  After this unit, students should

  • understand interface as a type for modeling "can do" behavior.
  • understand the subtype-supertype relationship between a class and its interfaces.