program to demonstrate single level inheritance

class Person {
  // Properties
  String? name;
  int? age;

  // Method
  void display() {
    print("Name: $name");
    print("Age: $age");
  }
}
// Here In student class, we are extending the
// properties and methods of the Person class
class Student extends Person {
  // Fields
  String? schoolName;
  String? schoolAddress;

  // Method
  void displaySchoolInfo() {
    print("School Name: $schoolName");
    print("School Address: $schoolAddress");
  }
}

void main() {
  // Creating an object of the Student class
  var student = Student();
  student.name = "John";
  student.age = 20;
  student.schoolName = "ABC School";
  student.schoolAddress = "New York";
  student.display();
  student.displaySchoolInfo();
}

________________________________________________________________________________________________________

Another example of single level inheritance

class Car {
  // Properties
  String? name;
  double? prize;
}

class Tesla extends Car {
  // Method to display the values of the properties
  void display() {
    print("Name: ${name}");
    print("Prize: ${prize}");
  }
}

void main() {
  // Create an object of Tesla class
  Tesla t = new Tesla();
  // setting values to the object
  t.name = "Tesla Model 3";
  t.prize = 50000.00;
  // Display the values of the object
  t.display();
}

________________________________________________________________________________________________________

Example of multilevel inheritance

class Car {
// Properties
String? name;
double? prize;
}

class Tesla extends Car {
// Method to display the values of the properties
void display() {
  print("Name: ${name}");
  print("Prize: ${prize}");
}
}

class Model3 extends Tesla {
// Properties
String? color;

// Method to display the values of the properties
void display() {
  super.display();
  print("Color: ${color}");
}
}

void main() {
// Create an object of Model3 class
Model3 m = new Model3();
// setting values to the object
m.name = "Tesla Model 3";
m.prize = 50000.00;
m.color = "Red";
// Display the values of the object
m.display();
}

________________________________________________________________________________________________________

Another example of multilevel inheritance

class Person {
  // Properties
  String? name;
  int? age;
}

class Doctor extends Person {
  // Properties
  List<String>? listofdegrees;
  String? hospitalname;

  // Method to display the values of the properties
  void display() {
    print("Name: ${name}");
    print("Age: ${age}");
    print("List of Degrees: ${listofdegrees}");
    print("Hospital Name: ${hospitalname}");
  }
}

class Specialist extends Doctor {
  // Properties
  String? specialization;

  // Method to display the values of the properties
  void display() {
    super.display();
    print("Specialization: ${specialization}");
  }
}

void main() {
  // Create an object of Specialist class
  Specialist s = new Specialist();
  // setting values to the object
  s.name = "John";
  s.age = 30;
  s.listofdegrees = ["MBBS", "MD"];
  s.hospitalname = "ABC Hospital";
  s.specialization = "Cardiologist";
  // Display the values of the object
  s.display();
}

________________________________________________________________________________________________________

Example of hierarchical inheritance

class Shape {
  // Properties
  double? diameter1;
  double? diameter2;
}

class Rectangle extends Shape {
  // Method to calculate the area of the rectangle
  double area() {
    return diameter1! * diameter2!;
  }
}

class Triangle extends Shape {
  // Method to calculate the area of the triangle
  double area() {
    return 0.5 * diameter1! * diameter2!;
  }
}

void main() {
  // Create an object of Rectangle class
  Rectangle r = new Rectangle();
  // setting values to the object
  r.diameter1 = 10.0;
  r.diameter2 = 20.0;
  // Display the area of the rectangle
  print("Area of the rectangle: ${r.area()}");

  // Create an object of Triangle class
  Triangle t = new Triangle();
  // setting values to the object
  t.diameter1 = 10.0;
  t.diameter2 = 20.0;
  // Display the area of the triangle
  print("Area of the triangle: ${t.area()}");
}

________________________________________________________________________________________________________

Program to demonstrate constructors in inheritance

class Laptop {
  // Constructor
  Laptop() {
    print("Laptop constructor");
  }
}

class MacBook extends Laptop {
  // Constructor
  MacBook() {
    print("MacBook constructor");
  }
}

void main() {
  var macbook = MacBook();
}

________________________________________________________________________________________________________

Example of constructor having parameters in inheritance

class Laptop {
  // Constructor
  Laptop(String name, String color) {
    print("Laptop constructor");
    print("Name: $name");
    print("Color: $color");
  }
}

class MacBook extends Laptop {
  // Constructor
  MacBook(String name, String color) : super(name, color) {
    print("MacBook constructor");
  }
}

void main() {
  var macbook = MacBook("MacBook Pro", "Silver");
}

________________________________________________________________________________________________________

Example of constructor in single level inheritance

class Person {
  String name;
  int age;

  // Constructor
  Person(this.name, this.age);
}

class Student extends Person {
  int rollNumber;

  // Constructor
  Student(String name, int age, this.rollNumber) : super(name, age);
}

void main() {
  var student = Student("John", 20, 1);
  print("Student name: ${student.name}");
  print("Student age: ${student.age}");
  print("Student roll number: ${student.rollNumber}");

}

________________________________________________________________________________________________________

Example of named constructor in inheritance

class Laptop {
  // Default Constructor
  Laptop() {
    print("Laptop constructor");
  }

  // Named Constructor
  Laptop.named() {
    print("Laptop named constructor");
  }
}

class MacBook extends Laptop {
  // Constructor
  MacBook() : super.named() {
    print("MacBook constructor");
  }
}

void main() {
  var macbook = MacBook();
}

________________________________________________________________________________________________________

Example of super keyword to refer to properties of parent class

class Car {
  int noOfSeats = 4;
}

class Tesla extends Car {
  int noOfSeats = 6;

  void display() {
    print("No of seats in Tesla: $noOfSeats");
    print("No of seats in Car: ${super.noOfSeats}");
  }
}

void main() {
  var tesla = Tesla();
  tesla.display();
}

________________________________________________________________________________________________________

example of calling constructor of parent class using super keyword

class Employee {
  // Constructor
  Employee(String name, double salary) {
    print("Employee constructor");
    print("Name: $name");
    print("Salary: $salary");
  }
}

class Manager extends Employee {
  // Constructor
  Manager(String name, double salary) : super(name, salary) {
    print("Manager constructor");
  }
}

void main() {
  Manager manager = Manager("John", 25000.0);
}

________________________________________________________________________________________________________