EEN512 Study Guide (19th November 1998)

• Object Oriented Design
  • Identify objects and relationships between them
  • Object Model Diagrams
    • Be able to construct one, or understand a given one
    • Meanings of the shapes: rectangles, diamonds, triangles
    • Meanings of connections and "blobs" on ends of connections
    • Classes, attributes, relationships, roles, link attributes
    • Difference between inheritance, membership, and relationship
    • Be able to convert diagram into C++ or Java definitions
    • And be able to do the reverse.
  • Using classes to encapsulate and hide implementation details
  • The dangers of trusting provided libraries
    • If the implementation is hidden from you, how do you know it is good?
    • (the example of thinking Java's Vector class is good for queues)
• Programming
  • IMPORTANT:
    • You are expected to know the basic principles of BOTH java and C++ and be able to understand both, and explain their ways of doing things and major differences, advantages, and disadvantages.
    • You are only expected to be reasonable proficient at programming in ONE of the langauges.
  • The differences between using objects and pointers to objects
  • Polymorphism via superclass pointers, "Object" in Java.
  • Creation of objects and arrays in C++ vs. in Java
  • Private, Protected, and Public members and inheritance
  • (Re-)defining operators in C++
  • overloaded method names and how methods are chosen
  • Constructors and operators automatically provided by C++
  • Virtual methods
    • Controversial use of p->method() when p is NULL
    • programming problems when null objects can't be used (tree example)
    • different implementations:
      • virtual method as member which is pointer to function
      • type tags in objects used to select from "dispatch tables"
  • Templates vs. Interfaces
• Active Objects
  • Really taking the "sending a message" model of method calling seriously
  • Adaptability to true parallel processing
  • Design insights sometimes leading to better non-active implementations
    • (remember the shortest path example for instance)
  • Implementation using threads
  • Problems of concurrent access to shared data:
    • Makes communication between threads difficult
    • Solution to the problem
• Java's Abstract Windows Toolkit (AWT)
  • The general hierarchy of classes
  • The style of programming
  • Components, Containers, Listeners, and Events.
• Proofs of Programs
  • The concept of "Weakest Precondition"
  • Basic rules for calculating wp(S,{Q}) where S is:
    • Assignment, Sequence(;), SKIP, Conditional.
  • Principles behind proofs of loops.

----------------------1st test, 29th September------------------

----------------------2nd test, 19th November-------------------

---------Final Examination, 5pm Tuesday 15th December-----------