Abstraction_Dart 

import 'dart:io';

/// Data Abstraction : show only functionality and hiding background details this called
/// data abstraction.
//  Abstract class
abstract class A {
  //  Abstract Method
  void getData();
  //  Abstract Method
  void showData();
}
//  Calling Abstract class
class B extends A {

  @override
  void getData() {
    print("Call from getData");
  }

  @override
  void showData() {
    print("Call from showData");
  }
}
void main() {
  B object = new B();
  object.getData();
  object.showData();
}

///You can create an object of concrete classes, but you cannot create an object of abstract classes.
///Abstract Class:
/// Abstract classes are classes that cannot be initialized. It is used to define the behavior
/// of a class that can be inherited by other classes. An abstract class is declared using
/// the keyword abstract.
/// Syntax:
// abstract class ClassName {
//   //Body of abstract class
//
//   method1();
//   method2();
// }

///Abstract Method
/// An abstract method is a method that is declared without an implementation.
/// It is declared with a semicolon (;) instead of a method body.
/// Syntax
// abstract class ClassName {
//   //Body of abstract class
//   method1();
//   method2();
// }

///Why We Need Abstract Class
/// Subclasses of an abstract class must implement all the abstract methods of the abstract class.
/// It is used to achieve abstraction in the Dart programming language.

/// Example 1: Abstract Class In Dart
/// In this example below, there is an abstract class Vehicle with two abstract methods start()
/// and stop(). The subclasses Car and Bike implement the abstract methods and override them
/// to print the message.

// abstract class Vehicle {
//   // Abstract method
//   void start();
//   // Abstract method
//   void stop();
// }
//
// class Car extends Vehicle {
//   // Implementation of start()
//   @override
//   void start() {
//     print('Car started');
//   }
//
//   // Implementation of stop()
//   @override
//   void stop() {
//     print('Car stopped');
//   }
// }
//
// class Bike extends Vehicle {
//   // Implementation of start()
//   @override
//   void start() {
//     print('Bike started');
//   }
//
//   // Implementation of stop()
//   @override
//   void stop() {
//     print('Bike stopped');
//   }
// }
//
// void main() {
//   Car car = Car();
//   car.start();
//   car.stop();
//
//   Bike bike = Bike();
//   bike.start();
//   bike.stop();
// }

///Note: The abstract class is used to define the behavior of a class that can be inherited by
/// other classes. You can define an abstract method inside an abstract class.

///Example 2: Abstract Class In Dart
/// In this example below, there is an abstract class Shape with one abstract method area()
/// and two subclasses Rectangle and Triangle. The subclasses implement the area() method and
/// override it to calculate the area of the rectangle and triangle, respectively.

// abstract class Shape {
//   int dim1, dim2;
//   // Constructor
//   Shape(this.dim1, this.dim2);
//   // Abstract method
//   void area();
// }
//
// class Rectangle extends Shape {
//   // Constructor
//   Rectangle(int dim1, int dim2) : super(dim1, dim2);
//
//   // Implementation of area()
//   @override
//   void area() {
//     print('The area of the rectangle is ${dim1 * dim2}');
//   }
// }
//
// class Triangle extends Shape {
//   // Constructor
//   Triangle(int dim1, int dim2) : super(dim1, dim2);
//
//   // Implementation of area()
//   @override
//   void area() {
//     print('The area of the triangle is ${0.5 * dim1 * dim2}');
//   }
// }
//
// void main() {
//   Rectangle rectangle = Rectangle(10, 20);
//   rectangle.area();
//
//   Triangle triangle = Triangle(10, 20);
//   triangle.area();
// }

///Constructor In Abstract Class:
/// You can’t create an object of an abstract class. However, you can define a constructor
/// in an abstract class. The constructor of an abstract class is called when an object
/// of a subclass is created.

///Example 3: Constructor In Abstract Class
/// In this example below, there is an abstract class Bank with a constructor which takes two
/// parameters name and rate. There is an abstract method interest(). The subclasses SBI and
/// ICICI implement the abstract method and override it to print the interest rate.

// abstract class Bank {
//   String name;
//   double rate;
//
//   // Constructor
//   Bank(this.name, this.rate);
//
//   // Abstract method
//   void interest();
//
//   //Non-Abstract method: It have an implementation
//   void display() {
//     print('Bank Name: $name');
//   }
// }
//
// class SBI extends Bank {
//   // Constructor
//   SBI(String name, double rate) : super(name, rate);
//
//   // Implementation of interest()
//   @override
//   void interest() {
//     print('The rate of interest of SBI is $rate');
//   }
// }
//
// class ICICI extends Bank {
//   // Constructor
//   ICICI(String name, double rate) : super(name, rate);
//
//   // Implementation of interest()
//   @override
//   void interest() {
//     print('The rate of interest of ICICI is $rate');
//   }
// }
//
// void main() {
//   SBI sbi = SBI('SBI', 8.4);
//   ICICI icici = ICICI('ICICI', 7.3);
//
//   sbi.interest();
//   icici.interest();
//   icici.display();
// }

///Key Points To Remember
/// You can’t create an object of an abstract class.
/// It can have both abstract and non-abstract methods.
/// It is used to define the behavior of a class that other classes can inherit.
/// Abstract method only has a signature and no implementation.

/// Abstraction Example
// void main()
// {
//   print("Enter the value of Number 1 : ");
//   var no1 = int.parse(stdin.readLineSync()!);
//   print("Enter the value of Number 2 : ");
//   var no2 = int.parse(stdin.readLineSync()!);
//
//   Addition additionObject = new Addition(no1, no2);
//   Subtraction subtractionObject = new Subtraction(no1, no2);
//   Multiplication multiplicationObject = new Multiplication(no1, no2);
//   Division divisionObject = new Division(no1, no2);
//
//   additionObject.calculation();
//   subtractionObject.calculation();
//   multiplicationObject.calculation();
//   divisionObject.calculation();
//
// }
// abstract class Mathematics
// {
//   int num1, num2;
//   Mathematics(this.num1, this.num2);
//
//   void calculation();
// }
// class Addition extends Mathematics
// {
//   Addition(super.num1, super.num2);
//
//   @override
//   void calculation() {
//     var sum = num1 + num2;
//     print("Addition is : ${sum}");
//   }
// }
// class Subtraction extends Mathematics
// {
//   Subtraction(super.num1, super.num2);
//
//   @override
//   void calculation() {
//     var sub = num1 - num2;
//     print("Subtraction is : ${sub}");
//   }
// }
// class Multiplication extends Mathematics
// {
//   Multiplication(super.num1, super.num2);
//
//   @override
//   void calculation() {
//     var mul = num1 * num2;
//     print("Multiplication is : ${mul}");
//   }
// }
// class Division extends Mathematics
// {
//   Division(super.num1, super.num2);
//
//   @override
//   void calculation() {
//     var div = num1 / num2;
//     print("Division is : ${div}");
//   }
// }

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