C# Abstraction

C# Abstraction

Data abstraction is the process of hiding certain details and showing only essential information to the user. Abstraction can be achieved with either abstract classes or interfaces.

Abstract Classes and Methods

The abstract keyword is used for classes and methods:

• Abstract class: is a restricted class that cannot be used to create objects (to access it, it must be inherited from another class).
• Abstract method: can only be used in an abstract class, and it does not have a body. The body is provided by the derived class (inherited from).

An abstract class can have both abstract and regular methods:

abstract class Animal
{
  public abstract void animalSound();
  public void sleep()
  {
    Console.WriteLine("Zzz");
  }
}

To access the abstract class, must inherit from another class. The derived class must implement the abstract methods using the override keyword.

using System;

abstract class Animal
{
  public abstract void animalSound();
  public void sleep()
  {
    Console.WriteLine("Zzz");
  }
}

class Pig : Animal
{
  public override void animalSound()
  {
    Console.WriteLine("The pig says: wee wee");
  }
}

class Program
{
  static void Main(string[] args)
  {
    Pig myPig = new Pig(); // Create a Pig object
    myPig.animalSound();  // Call the abstract method
    myPig.sleep();        // Call the regular method
  }
}