OOAD Interview Questions and Answers

OOAD -Object-Oriented Design: The emphasis in programming methods is primarily on the proper and effective use of particular language mechanisms. By contrast, design methods emphasize the proper and effective structuring of a complex system. We can herewith list of latest and updated OOAD Interview Questions and their answers for fresher’s as well as experienced users.  These JavaScript interview question covers latest version of OOAD. 

Object-oriented analysis and design is the method we introduced. Its underlying concept is that one should model software systems as collections of cooperating objects, treating individual objects as instances of a class within a hierarchy of classes. Object-oriented analysis and design directly reflects the topology of more recent high-order programming languages such as Smalltalk, Object Pascal, C++, the Common Lisp Object System (CLOS), and Ada.

Best OOAD Interview Questions and Answers

There are two important parts to this definition: object-oriented design (1) leads to an object-oriented decomposition and (2) uses different notations to express different models of the logical (class and object structure) and physical (module and process architecture) design of a system, in addition to the static and dynamic aspects of the system. Here you can find top best OOAD Interview Questions and Answers for beginners and professionals,

What do you mean by analysis and design?

Analysis: Basically, it is the process of determining what needs to be done before how it should be done. In order to accomplish this, the developer refers the existing systems and documents. So, simply it is an art of discovery.

Design: It is the process of adopting/choosing the one among the many, which best accomplishes the user’s needs. So, simply, it is compromising mechanism.

What are the steps involved in designing?

Before getting into the design the designer should go through the SRS prepared by the System Analyst. The main tasks of design are Architectural Design and Detailed Design.

In Architectural Design we find what are the main modules in the problem domain. In Detailed Design we find what should be done within each module.

What are the main underlying concepts of object orientation?

Objects, messages, class, inheritance and polymorphism are the main concepts of object orientation.

What do u mean by SBI of an object?

SBI stands for State, Behavior and Identity. Since every object has the above three. State:

It is just a value to the attribute of an object at a particular time.

Behaviour: It describes the actions and their reactions of that object.

Identity: An object has an identity that characterizes its own existence. The identity makes it possible to distinguish any object in an unambiguous way, and independently from its state.

Differentiate persistent & non-persistent objects?

Persistent refers to an object’s ability to transcend time or space. A persistent object stores/saves its state in a permanent storage system without losing the information represented by the object.

A non-persistent object is said to be transient or ephemeral. By default, objects are considered as non-persistent.

What do you meant by static and dynamic modeling?

Static modelling is used to specify structure of the objects that exist in the problem domain. These are expressed using class, object and USECASE diagrams.

But Dynamic modeling refers representing the object interactions during runtime. It is represented by sequence, activity, collaboration and statechart diagrams.

How to represent the interaction between the modeling elements?

Model element is just a notation to represent (Graphically) the entities that exist in the problem domain. e.g. for modeling element is class notation, object notation etc. Relationships are used to represent the interaction between the modeling elements. The following are the Relationships. 

Why generalization is very strong?

Even though Generalization satisfies Structural, Interface, Behaviour properties. It is mathematically very strong, as it is Antisymmetric and Transitive.

Antisymmetric: employee is a person, but not all persons are employees. Mathematically all As’ are B, but all Bs’ not A. Transitive: A=>B, B=>c then A=>c. 

Differentiate Aggregation and containment?

Aggregation is the relationship between the whole and a part. We can add/subtract some properties in the part (slave) side. It won’t affect the whole part.

Best example is Car, which contains the wheels and some extra parts. Even though the parts are not there we can call it as car.

But, in the case of containment the whole part is affected when the part within that got affected. The human body is an apt example for this relationship. When the whole body dies the parts (heart etc) are died.

Can link and Association applied interchangeably?

No, You cannot apply the link and Association interchangeably. Since link is used represent the relationship between the two objects.

But Association is used represent the relationship between the two classes. link:: student:Abhilash course:MCA Association:: student course 

Why is planning too much up front a mistake in an OOSAD?

You can’t plan only for the current phase of the project as your future activities are still coarse granular. To have good planning you need to have fine granularity w.r.t the tasks to get clear WBS

Why should project managers complete hard problems first in an OOSAD project?

The query actually holds good in general for every situation in life. It is one of the principles of good time management. The idea is to tackle hard (and important) problems first. This, if resolved – will pep up your confidence to deal with other not so hard issues. Also, this could have cascading effect on other issues that may get resolved on its own.

I would rather stress on “important” than “hard” issues. If a “hard” problem is not coming in the way of your deliverables (means it is not important) – keep it aside. There is no need to spend a lot of time on it.

Why does the function arguments are called as signatures?

The arguments distinguish functions with the same name (functional polymorphism). The name alone does not necessarily identify a unique function. However, the name and its arguments (signatures) will uniquely identify a function.

Object-oriented design is a method of design encompassing the process of object-oriented decomposition and a notation for depicting both logical and physical as well as static and dynamic models of the system under design.

A methodology is a collection of methods applied across the software development life cycle and unified by some general, philosophical approach. Methods are important for several reasons. Foremost, they instill a discipline into the development of complex software systems. They define the products that serve as common vehicles for communication among the members of a development team. Additionally, methods define the milestones needed by management to measure progress and to manage risk.

Thus, the compilation of these OOAD Interview questions includes some of the major points that can be asked during an interview. The OOAD interviewers generally check the base knowledge of a candidate, which can be gained by practicing these OOAD questions prior interview.