Session 21

Question 1

Object Modeling

Answer 1

Technique for identifying object w/in the systems enviro & the relationships btw the objects

Question 2

Whats OOAD

Answer 2

Object Oriented Analysis and Design
Approach of using object modeling during systems analysis and design

Question 3

What are the advantages of OOAD

Answer 3

• Small semantic gap since real world occurrences directly mapped to objects in model
  (reduces the “translation gap” between how things work in the real world and how we model them in software)
• Combination of process and data modeling
  ( merges what the system does (process) with what the system knows (data) into a single view.)
• Improved communication btw users, analysts, designers, and programmers
  (creates models that are easier for everyone to understand, not just programmers)
• Represents commonality among system components
  (uses inheritance and abstraction to capture shared features among different components.)
• Reusability of analysis, design, and programming results
  (Once an object or class is defined, it can often be reused in other systems)
• Increased consistency among models developed during analysis, design and programming
  (The same concepts (objects, classes, methods) are used across all phases of development.)

Question 4

Whats an object

Answer 4

An abstraction of something in a problem domain
An entity with a well-defined boundary

Question 5

Whats an attribute

Answer 5

Characteristics of an object

Question 6

What are operations

Answer 6

Things that objects can do and
functions that act on the object’s attribute
Either command/question

Question 7

What is a class?

Answer 7

A description of a group of objects with common attributes, operations, and relationships

Question 8

Can a question change the state of an object?

Answer 8

no

Question 9

Can a command change the state of an object

Answer 9

Yes

Question 10

What are the types of relationships

Answer 10

Association and Generalization

Question 11

What association

Answer 11

Models a semantic connection among
classes
Represents structural relationships between classes

Question 12

Whats generalization/inheritance

Answer 12

A relationship among classes where subclasses share the attributes and operations of superclasses
Defines a hierarchy of abstractions in which a subclass inherits from one or more superclasses

Question 13

What is inherited?

Answer 13

Attributes
Operations
Relationships