// Define a class named Person with properties and methods

class Person {

  String name;

  int age;

​

  void introduceYourself() {

    print("Hello, my name is $name and I am $age years old.");

  }

}

​

void main() {

  // Create an instance of the Person class

  var person = Person();

  // Set the values for the person's name and age

  person.name = "John";

  person.age = 25;

  // Call the introduceYourself method

  person.introduceYourself(); // Output: Hello, my name is John and I am 25 years old.

}

// Class Declaration 

class AClass {}

​

void main() {

  // Object creation

  var a = AClass();

​

  // Access Object property

  print(a.hashCode);

  print(a.runtimeType);

  // Access String Object method

  print("vel".toUpperCase());

​

  // Access int property

  print(2.isNegative);

  print(2.runtimeType);

}