Object Oriented programming in C#:
Object Oriented programming is a programming style which is associated with the concepts like class, object, Inheritance, Encapsulation, Abstraction, Polymorphism.
Class: A class is a collection of method and variables.
Class: A class is a collection of method and variables.
We can define a class using the class keyword and the class body enclosed by a pair of curly braces, as shown in the following example:
public class A
{
}
{
}
Inheritance: Inheritance feature allows code reusability when a class includes property of another class. In C# “:” is used to represent inheritance, as shown in the following example:
public class Papa {
}
class Child : Papa {
}
}
class Child : Papa {
}
Objects: Object is a component of a program that knows how to perform certain actions and how to interact with other elements of the program, as shown in the following example:
Rectangle Rect = new Rectangle();
Here, Rectangle is a class, Rect is an object of class Rectangle, new is a keyword, Rectangle() is a constructor of class Rectangle.
Abstraction: Abstraction can be achieved using abstract classes in C#. Abstract classes contain abstract methods, which are implemented by the derived class.
Encapsulation: Encapsulation means bundling of data and methods within one unit, e.g., a class in C#. Encapsulation enables a programmer to implement the desired level of abstraction.
Polymorphism: Polymorphism means overloading and overriding, as shown in the following example:
Polymorphism overloading example:
using System;
namespace PolyOverloadingExample
{
public class OverLoading
{
public void sum(int a, int b)
{
Console.WriteLine(a + b);
}
public void sum(int a, int b, int c)
{
Console.WriteLine(a + b + c );
}
}
namespace PolyOverloadingExample
{
public class OverLoading
{
public void sum(int a, int b)
{
Console.WriteLine(a + b);
}
public void sum(int a, int b, int c)
{
Console.WriteLine(a + b + c );
}
}
}
Polymorphism overriding example:
using System;
namespace PolyOverridingExample
{
public class Parent
{
public virtual void Show()
{
Console.WriteLine(“Welcome”);
}
}
public class Child:Parent
{
public override void Show()
{
Console.WriteLine(“Swagatam”);
}
}
namespace PolyOverridingExample
{
public class Parent
{
public virtual void Show()
{
Console.WriteLine(“Welcome”);
}
}
public class Child:Parent
{
public override void Show()
{
Console.WriteLine(“Swagatam”);
}
}
}
Viva Vice on OOP in C#
Q1. The capability of an object in Csharp to take number of different forms and hence display behaviour as according is known as:-
Ans. Polymorphism.
Q2. Which of the following keyword is used to change data and behavior of a base class by replacing a member of the base class with a new derived member?
Ans. New.
Q3. What is the correct way to overload +operator?
Ans. public sample operator + ( sample a, sample b), public abstract operator + (sample a,sample b).
Q4. Selecting appropriate method out of number of overloaded methods by matching arguments in terms of number,type and order and binding that selected method to object at compile time is called?
Ans. Compile time polymorphism.
Q5. Correct syntax for while statement is:-
Ans.
while(condition)
{
}
References:
- Sebesta,”Concept of programming Language”, Pearson Edu
- Louden, “Programming Languages: Principles & Practices” , Cengage Learning
- Tucker, “Programming Languages: Principles and paradigms “, Tata McGraw –Hill.
- E Horowitz, “Programming Languages”, 2nd Edition, Addison Wesley