OOP questions for Computer Science and MCA students

What are the advantages of object oriented approach?

• It is a programming paradigm that uses 'objects' and their interactions to design applications and computer programs.

• It emphasis on data rather than procedure.
• The objects can communicate with each other through the functions.
• New data and functions can be easily added whenever necessary.
• It follows bottom-up approach.
• The data is hidden and cannot be accessed by external functions.

• It is the next great advance in software engineering.
• It reduces development time and resources required to maintain existing applications.
• It increases code reuse.
• It provides a competitive advantage to organizations that use it.

• Encapsulation
• Objects
• Class and Inheritance
• Instances and Instantiation
• Methods and Messages

• The software objects model complexity is reduced and the program structure is very clear.

• It is a desired goal of all development process.
• It contains both data and functions which act on data.
• It makes easy to reuse the code in a new system.
• Messages provide a predefined interface to an object's data and functionality.

• This feature increases in quality are largely a by-product of this program reuse.

• The OOP method makes the code more maintainable.
• The objects can be maintained separately, locating and fixing problems easier.

• The object oriented applications are more scalable than structured approach.
• It makes easy to replace the old and aging code with faster algorithms and newer technology.

• The OOD systems are easier to modify.
• It can be altered in fundamental ways without ever breaking up since changes are neatly encapsulated.

• It is easy to make minor changes in the data representation or the procedures in an object oriented program.

• It involves the transmission of messages back and forth over a network.

Write a note on interaction overview diagram.

• It is a variant of the Activity Diagram where the nodes are the interactions or interaction occurrences.
• It focuses on the overview of the flow of control of the interactions.
• It describes the interactions where messages and lifelines are hidden.
• It looks like activity diagrams that can only have inline interactions or interaction uses instead of invocation actions.
• UML 2.4 requires branching and joining of branches in interaction overview diagrams to be properly nested.
• This is more restrictive than in activity diagrams and could be quite difficult to obey.
• It combines element from activity and interaction diagram.




• The Lifelines and Messages do not appear in this overview level.

• An activity may have more than one activity final node. The first one reached stops all flows in the activity.

• It is an edge that starts an activity node after the previous one is finished.

• It accepts tokens on an incoming edge and presents them to multiple outgoing edges.

• It is a control node at which flow starts when the activity is invoked.

• It gives the ability to attach various remarks to the elements.
• It carries no semantic force, but may contain information that is useful to a modeler.