Lesson Two

Dr. James E. Tomayko

Lesson Two Objectives

1. Be able to explain the difference between the topologies of "verb-based" versus "noun-based" systems.

2. Be able to list the three elements of an object-based program.

3. Be able to define the difference between analysis and design.

4. Be able to identify abstractions in a problem domain.

5. Be able to encapsulate functions.

6. Be able to create cohesive modules.

1. Older generation programming languages tend to have flat topologies and are based on the development of procedures and functions. Object-based systems tend to be organized around representations of real-world objects. Booch suggests that if we consider procedures and functions to be verbs and objects to be nouns, then we can imagine the different organizations more clearly.

   Take a verb-based system you have developed and explain how it might be implemented by focusing on the nouns that describe it.

2. What are the three elements needed to make a program truly object-oriented?

3. What is the difference between object-oriented design and object-oriented analysis?

4. Choose some subset of a project on which you are working.

   	a. Define an abstraction that enables you to define an entity that
   	    can interact with other entities in your problem domain.
   
   	b. What parts of your abstraction need to be known to the 
   	    other entities? What parts can be kept private?
   
   	c. Give an example of a logical grouping of abstractions into a 
   	    module. Why do these abstractions make sense as a unit?
   

5. What is the difference between a superclass and a subclass?

6. How does object-based design assist in developing concurrent systems?