Java Interview Questions

Applications Of OOP

• Real time systems
• Simulation and modelling
• Object-oriented databases
• Hypertext,hypermedia and expertext
• AI and expert systems
• Neural networks and parallel programming
• decision support and office automation systems
• CIM/CAD/CAD systems

OOP offers several benefits to both the program designer and the user.Object orientation contibutes to the solution of many problems associated with the development and quality of software products.

• Through inheritence,we can eliminate redundent code and extend the use of existing classes.
• We can build programs from the standard working modules that communicate with one another,rather than having to start writing the code from scracth.This leads to saving of development time and higher productivity,
• The principle of data hiding helps the programmer to build seure programs that cannot be invaded by code in other parts of programs.
• It is possible to have multiple objects to coexist without any interfrence.
• It is possible to map objects in the problem domain to those objects in the program.
• It is easy to partition the work in a project based on objects.
• The data-centered design approach enables us to capture more details of a model in an implemetable form.
• Object-oriented systems can be easily upgraded from small to large systems.
• Message passing techniques for communication between objects make the interface descriptions with external systems much simpler.
• Software complexity can be easily managed.

Encapsulation
Abstraction
Polymorphism
Inheritance

Abstraction

• It is a simplified description  or  specification of a object
• It  hides  the complexity  of an object & allows you deal with  the features  that needed.
• It allows to ignore the redundant features of an object and to concentrate  on essential characteristics of the object.

Encapsulation

• It is a mechanism that binds data and the functions which operate on it
• It allows to carry the data and operations together as a single unit.
• It facilitates Data Hiding.

Inheritance

• It is a process by which one object acquires the features of another.
• It is a concept of reusability and extendability
• It is also called as  is - a  relationship.

Polymorphism

Polymorphism is a mechanism through which one object can exhibit many forms that depends on situation