difference between abstraction and abstract class ?

ashutosh parmar

6y5.2kVisual Basic .NET

Dear Sir,

I read somewhere that we can achive abstraction using abstract class.

Is there any difference or both are same.

6 Replies

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Roshan Patil6y ago
Dear Aushitosh,
You do not need to achieve abstraction, it is proivded by OOP itself. So every OOP compliant language provides abstraction.
Abstraction : Representing the essential features of something without including background or inessential detail to do some work easily. Its representation of an actual item.
General Example : In washin machine we have given buttons to add water, add ditergent, set rinse time and set dry time. We havent exposed or we don't care how actually its is working inside.

The program workes on object of a class. For the program to work on object of a class, it is not necessary to understand how the actions (methods) of the class are working or how the data of the class is working inside the actions of the class. All it wants to know is what data (variables, properties etc) it has got and what actions (methods) it can perform. Not How.
So abstraction is achived using data members and member functions. When we use the class by creating its object, only data members and members functions are shared (not the code inside it).

For Abstract Class and other types of classes refer : https://www.c-sharpcorner.com/article/types-of-classes-and-their-characteristics/
Abstract class provide abstraction. While inheriting an abstract class, It tells us what all functionality it can provide. It has got abstract actions for which code will be written by the inheriting class.
Ashutosh Gupta6y ago
hello ashutosh.
you can implement abstraction in c# by using abstract keyword, makring class as abstract which can have abstract method. abstract is used mostly when you define your base class and the class will be derived by many other classes. it contains all base common functionality, similar to interface but this is class so contains abstrct methods defination + implemenration of other methods. in simple words if you have Compnay class that is abstract which can have base properties like name, address, CalculateTax() where Tax of each compnay may vary on their compmany income etc.
public abstract class BaseCompnay
{
public string name;
public string address;
public int TotalEmployee;
public int TotalIncome;

public abstract int CalculateTax();
}

public class XCompnay : BaseCompnay
{
public override int CalculateTax()
{
return 1; // calculate tax based on compnay income + no of empoyee etc
}
}

public class YCompnay : BaseCompnay
{
public override int CalculateTax()
{
return 2; // calculate tax based on compnay income + no of empoyee etc
}
}

now when you have object of Ycompany and call calculateTax method, it returns to 2, as compiler understand this method is overridden by this derived class.

you can also mark the abstract method as virtual if you have any default value to return
Note - abstract class can also have virtual method too.
Jaish Mathews6y ago
Its like sweet and sugar. Sweet is a noun there always, but we can only experience it after making sugar. Sameway abstraction is noun and therei n oops for long time. If you want to experience it, use abstarct class or interface or even using normal class.

Below is a sample using abstract class. Abstract classes contain abstract methods, which are implemented by the derived class. The derived classes have more specialized functionality.
using System;
namespace Demo {
   abstract class Shape {
      public abstract int area();
   }

   class Rectangle:  Shape {
      private int length;
      private int width;

      public Rectangle( int a = 0, int b = 0) {
         length = a;
         width = b;
      }
      public override int area () {
         Console.WriteLine("Rectangle class area :");
         return (width * length);
      }
   }
Above you see that abstarct class not revealing the implementation details of method area(). An inherited class can implement area(). In above code, class Rectangle has implemented it's own areas().
Later, another class Triangle can also implement it's own version of areas() by deriving from Shape class. So here we do abstraction in an abstract class and real implementation is inside derived class.

Ref. https://www.tutorialspoint.com/What-is-abstraction-in-Chash
Mageshwaran R6y ago
Hi ashutosh parmar:

"Abstract" is an antonym of "concrete". With abstractions you represent notions and ideas, rather than the concrete way these ideas are implemented. This fits into your understanding of abstraction - you are hiding the details and you only show the interface.
Abstraction is one of the oops concept. Abstraction can be achieved by abstract classes by using abstract key word. Abstraction gives general information like common functionality briefly. Abstraction tells us what the object does instead of how it does it.
The abstract classes defines an interface which the users of the class will use. An abstract class is similar to an interface except that some method can be implemented and all the abstracts ones will be implemented by the concrete classes that extends it. In summary the advantage is that you can have multiple implementations of the same abstract class that are completely interchangeable because the class that user operate with, is of the abstract type rather than of a specific implementation type.
Abstract class is a class which can't instantiate and Which forces the derived classes to implement this abstract class. Abstract class comprises both abstract methods & non abstract methods. Abstract methods must be implemented in derived classes. Abstract class is a partially abstract class.
Example:
abstract class CurryBase
{
public abstract void doCurryMasala();
}
public class FishCurry : CurryBase
{
public void doCurryMasala()
{
// Add Fish Curry specific contents also.
}
}
ashutosh parmar6y ago
Dear Krishna,

How can we achieve abstraction in C#?
can you explain in brief?
Krishna Rajput Singh6y ago
Hi ashutosh,
abstraction is an oops concept that hiding the data value or data members and showing only essential data that need to show to the user.
while abstract class is the type of class while writing the abstract keyword in any before the class name that class called abstract class. if you declare any type of abstract method in any class then you need to assign that class as abstract class. abstract class, we can't create an object.

more info visit below link
https://www.c-sharpcorner.com/interview-question/what-is-difference-between-abstraction-and-abstract-class