Object Oriented Programming Design CST33 III –Semester
Subject Name: OBJECT ORIENTED PROGRAMMING DESIGN
Subject Code: CS T33
2 MARKS AND 11 MARKS
UNIT V
Object Modelling and Object Oriented Software development: Overview of OO concepts –
UML – Use case model – Class diagrams – Interaction diagrams – Activity diagrams – state
chart diagrams - Patterns – Types – Object Oriented Analysis and Design methodology –
Interaction Modelling – OOD Goodness criteria.
PART A – 2 MARK QUESTIONS
1. What Is Object Oriented Analysis and Design?
During object-oriented analysis, there is an emphasis on finding and describing the
objects—or concepts—in the problem domain. For example, in the case of the library
information system, some of the concepts include Book, Library, and Patron.
During object-oriented design, there is an emphasis on defining software objects and how
they collaborate to fulfill the requirements. For example, in the library system, a Book
software object may have a title attribute and a get Chapter method
2. What are the rules of UML?
The rules of UML are:
Names What you call things, relationships, and diagrams
Scope The context that gives specific meaning to a name
Visibility How those names can be seen and used by others
Integrity How things properly and consistently relate to one Another.
Execution What it means to run or simulate a dynamic model.
,Object Oriented Programming Design CST33 III –Semester
3. Define UML(unified modeling language)
UML, as the name implies, is a modeling language. It may be used to visualize, specify,
construct, and document the artifacts of a software system. It provides a set of notations
(e.g. rectangles, lines, ellipses, etc.) to create a visual model of the system. Like any other
language, UML has its own syntax (symbols and sentence formation rules) and semantics
(meanings of symbols and sentences). Also, we should clearly understand that UML is
not a system design or development methodology, but can be used to document object-
oriented and analysis results obtained using some methodology.
4. Define Object Oriented Analysis?
Object Oriented Analysis (OOA) is a method of analysis that examines requirements
from the perspective of the classes and objects found in the vocabulary of the problem
domain.
5. What are the primary goals in the design of UML?
Provide users a ready – to use expressive visual modeling language so they can
develop and exchange meaningful models.
• Provide extensibility and specialization mechanism to extend the core concepts.
• Be independent of particular programming language and development process.
• Provide a formal basis for understanding the modeling language.
• Encourage the growth of the OO tools market.
• Support higher – level development concepts.
• Integrate best practices and methodologies.
6. What is interaction diagram? Mention the types of interaction diagram.
Interaction diagrams are diagrams that describe how groups of objects collaborate to
get the job done interaction diagrams capture the behavior of the single use case,
showing the pattern of interaction among objects.
There are two kinds of interaction models
• Sequence Diagram
• Collaboration Diagram.
7. What is Collaboration Diagram?
Collaboration diagram represents a collaboration, which is a set of objects related in
a particular context, and interaction, which is a set of messages exchanged among
the objects with in collaboration to achieve a desired outcome.
8. Define Pattern?
A pattern is a named problem/solution pair that can be applied in new context, with
advice on how to apply it in novel situations and discussion of its trade-offs.
,Object Oriented Programming Design CST33 III –Semester
9. What is Observer pattern?
The observer pattern (a subset of the publish/subscribe pattern) is a software design
pattern in which an object, called the subject, maintains a list of its dependents,
called observers, and notifies them automatically of any state changes, usually by
calling one of their methods. It is mainly used to implement distributed event
handling systems.
10. Define Start chart Diagram.
Start chart diagram shows a sequence of states that an object goes through during its
life in response to events. A state is represented as a round box, which may contain
one or more compartments. The compartments are all optional.
11. Define Low Coupling?
Low Coupling is an evaluative pattern, which dictates how to assign responsibilities
to support:
• low dependency between classes;
• low impact in a class of changes in other classes;
• high reuse potential;
12. Define High Cohesion?
High Cohesion is an evaluative pattern that attempts to keep objects appropriately
focused, manageable and understandable. High cohesion is generally used in support of
Low Coupling. High cohesion means that the responsibilities of a given element are
strongly related and highly focused. Breaking programs into classes and subsystems is an
example of activities that increase the cohesive properties of a system.
13. What is Facade Pattern?
A facade is an object that provides a simplified interface to a larger body of code, such as
a class library. A facade can:
• make a software library easier to use, understand and test, since the facade has
convenient methods for common tasks;
• make code that uses the library more readable, for the same reason;
• reduce dependencies of outside code on the inner workings of a library, since most code
uses the facade, thus allowing more flexibility in developing the system;
, Object Oriented Programming Design CST33 III –Semester
• Wrap a poorly-designed collection of APIs with a single well-designed API (as per task
needs).
14. What is the main advantage of object oriented development?
• High level of abstraction
• Seamless transition among different phases of software development
• Encouragement of good programming techniques.
• Promotion of reusability.
15. What do you mean by information hiding?
Information hiding is the principle of concealing the internal data and procedures of an
object and providing an interface to each object and providing an interface to each object
in such a way as to reveal as little as possible about its inner workings.
An object is often said to encapsulate the date
and a program.
Per-class protection.
• Class methods can access any object of that class and not just the
receiver
Per-object protection.
• Methods can access only the receiver.
16. Explain object relationship and associations?
a. Association represents the relationships between objects and classes.
b. Associations are bidirectional.
c. Cardinality specifies how many instances of one class may relate to a single instance of
an associated class.
d. Cardinality constraints the number of related objects and often is described as being
“one” or “many”
Subject Name: OBJECT ORIENTED PROGRAMMING DESIGN
Subject Code: CS T33
2 MARKS AND 11 MARKS
UNIT V
Object Modelling and Object Oriented Software development: Overview of OO concepts –
UML – Use case model – Class diagrams – Interaction diagrams – Activity diagrams – state
chart diagrams - Patterns – Types – Object Oriented Analysis and Design methodology –
Interaction Modelling – OOD Goodness criteria.
PART A – 2 MARK QUESTIONS
1. What Is Object Oriented Analysis and Design?
During object-oriented analysis, there is an emphasis on finding and describing the
objects—or concepts—in the problem domain. For example, in the case of the library
information system, some of the concepts include Book, Library, and Patron.
During object-oriented design, there is an emphasis on defining software objects and how
they collaborate to fulfill the requirements. For example, in the library system, a Book
software object may have a title attribute and a get Chapter method
2. What are the rules of UML?
The rules of UML are:
Names What you call things, relationships, and diagrams
Scope The context that gives specific meaning to a name
Visibility How those names can be seen and used by others
Integrity How things properly and consistently relate to one Another.
Execution What it means to run or simulate a dynamic model.
,Object Oriented Programming Design CST33 III –Semester
3. Define UML(unified modeling language)
UML, as the name implies, is a modeling language. It may be used to visualize, specify,
construct, and document the artifacts of a software system. It provides a set of notations
(e.g. rectangles, lines, ellipses, etc.) to create a visual model of the system. Like any other
language, UML has its own syntax (symbols and sentence formation rules) and semantics
(meanings of symbols and sentences). Also, we should clearly understand that UML is
not a system design or development methodology, but can be used to document object-
oriented and analysis results obtained using some methodology.
4. Define Object Oriented Analysis?
Object Oriented Analysis (OOA) is a method of analysis that examines requirements
from the perspective of the classes and objects found in the vocabulary of the problem
domain.
5. What are the primary goals in the design of UML?
Provide users a ready – to use expressive visual modeling language so they can
develop and exchange meaningful models.
• Provide extensibility and specialization mechanism to extend the core concepts.
• Be independent of particular programming language and development process.
• Provide a formal basis for understanding the modeling language.
• Encourage the growth of the OO tools market.
• Support higher – level development concepts.
• Integrate best practices and methodologies.
6. What is interaction diagram? Mention the types of interaction diagram.
Interaction diagrams are diagrams that describe how groups of objects collaborate to
get the job done interaction diagrams capture the behavior of the single use case,
showing the pattern of interaction among objects.
There are two kinds of interaction models
• Sequence Diagram
• Collaboration Diagram.
7. What is Collaboration Diagram?
Collaboration diagram represents a collaboration, which is a set of objects related in
a particular context, and interaction, which is a set of messages exchanged among
the objects with in collaboration to achieve a desired outcome.
8. Define Pattern?
A pattern is a named problem/solution pair that can be applied in new context, with
advice on how to apply it in novel situations and discussion of its trade-offs.
,Object Oriented Programming Design CST33 III –Semester
9. What is Observer pattern?
The observer pattern (a subset of the publish/subscribe pattern) is a software design
pattern in which an object, called the subject, maintains a list of its dependents,
called observers, and notifies them automatically of any state changes, usually by
calling one of their methods. It is mainly used to implement distributed event
handling systems.
10. Define Start chart Diagram.
Start chart diagram shows a sequence of states that an object goes through during its
life in response to events. A state is represented as a round box, which may contain
one or more compartments. The compartments are all optional.
11. Define Low Coupling?
Low Coupling is an evaluative pattern, which dictates how to assign responsibilities
to support:
• low dependency between classes;
• low impact in a class of changes in other classes;
• high reuse potential;
12. Define High Cohesion?
High Cohesion is an evaluative pattern that attempts to keep objects appropriately
focused, manageable and understandable. High cohesion is generally used in support of
Low Coupling. High cohesion means that the responsibilities of a given element are
strongly related and highly focused. Breaking programs into classes and subsystems is an
example of activities that increase the cohesive properties of a system.
13. What is Facade Pattern?
A facade is an object that provides a simplified interface to a larger body of code, such as
a class library. A facade can:
• make a software library easier to use, understand and test, since the facade has
convenient methods for common tasks;
• make code that uses the library more readable, for the same reason;
• reduce dependencies of outside code on the inner workings of a library, since most code
uses the facade, thus allowing more flexibility in developing the system;
, Object Oriented Programming Design CST33 III –Semester
• Wrap a poorly-designed collection of APIs with a single well-designed API (as per task
needs).
14. What is the main advantage of object oriented development?
• High level of abstraction
• Seamless transition among different phases of software development
• Encouragement of good programming techniques.
• Promotion of reusability.
15. What do you mean by information hiding?
Information hiding is the principle of concealing the internal data and procedures of an
object and providing an interface to each object and providing an interface to each object
in such a way as to reveal as little as possible about its inner workings.
An object is often said to encapsulate the date
and a program.
Per-class protection.
• Class methods can access any object of that class and not just the
receiver
Per-object protection.
• Methods can access only the receiver.
16. Explain object relationship and associations?
a. Association represents the relationships between objects and classes.
b. Associations are bidirectional.
c. Cardinality specifies how many instances of one class may relate to a single instance of
an associated class.
d. Cardinality constraints the number of related objects and often is described as being
“one” or “many”
