oops concept in .net interview questions and answers, object oriented programming coneps in .net ~ For Job Seekers

oops concept in .net interview questions and answers, object oriented programming coneps in .net

Hi welcome Back to Dotnet section today i would like to share more .net interview questions and answers on Topic oops.

1). what are the different types of inheritance.

Inheritance in OOP is of four types:

Single inheritance - Contains one base class , one derived class
Hierarchical inheritance - Contains one base class and the multiple derived classes of the same base class
Multilevel inheritance - Contains a class derived from the derived class
Multiple inheritance - Contains several base classes and the derived class

2)What do you mean by term data encapsulation?

Data encapsulation is a concept of binding data and code in single unit called object and hiding all implementation details of a class from the user. It prevents unauthorized access of data and restricts user to use the necessary data only.

3). What is the difference between procedural and object-oriented programming Explian?

Procedural programming is based upon modular approach in which the larger programs are broken into procedures. Each procedure is a set of instructions that are executed one after another. whereas OOP is based upon the objects. An object consists of various elements such as methods and variables.
And morever Access modifiers are not used in procedural programming, which implies that the entire data can be accessed freely anywhere in the program. In OOP, you can specify the scope of a particular data by using access modifiers - public, private, internal, protected, and protected internal.

49. What are different ways method can be overloaded?

The different ways to overload a method are as follows:

By changing number of parameters used
By changing order of parameters
By using different data types for parameters

4. Give the difference between an abstract class and an interface.

Abstract Class:

class can extend only one abstract class
members of abstract class can be private as well as protected.
Abstract classes should have the subclasses
Any class can extend from an abstract class.
Methods in a abstract class can be abstract as well as concrete.
There can be a constructor for the abstract class.
The class extending abstract class may or may not implement any of its method.
abstract class can implement methods.

Interface

class can implement several interfaces
An interface can only have the public members.
Interfaces must have implementations by classes
Only an interface can extend from another interface.
All methods in an interface should be abstract
Interface does not have a constructor.
All methods of interface need to be implemented by a class implementing that interface.
Interfaces cannot contain body of th eany of its method.