class_concept

void main() {
  var saigopi = Human();
  // saigopi.name = "Sai Gopi N";
  print("name is ${saigopi.name}");
  saigopi.sleep();

  var myConstructor = Human.myConstuctor();

  var sum = myConstructor.addTwoNumbers(190, 20);

  print("In Main >> sum is $sum");

  // var kelvin = Human();
  // kelvin.name = "Kelvin Josh";
  // kelvin.sleep();

  var ram = Student(5035, "Flutter");
  // ram.sNo = 12;
  // print("Roll Number is : " + ram.getRollNumber().toString());
  print("Roll Number is : ${ram.getRollNumber()}");
}

class Student {
  var sNo;

  // Student(var rollNumber) {
  //   sNo = rollNumber;
  //   print("rollNumber is $sNo");
  // }

  var name;

  Student(this.sNo, this.name) {
    print('Name is $name');
  }

  getRollNumber() {
    return sNo;
  }
}

class Human {
  // properties (variables)
  var name;
  // functions/method
  // syntax: function_name(){}
  void sleep() {
    print('$name is sleeping');
  }

  int addTwoNumbers(var x, var y) {
    // var x = 10, y = 20; static way
    // print('sum is ${x + y}');
    return x + y;
  }

  automaticChecking() {
    print('i am checking the status ... ');
  }

  // constructor
  Human() {
    print('Human constructor has created');
    automaticChecking();
  }
  // getters/setters
  // this x is age
  // var age;

  // named constructor
  Human.myConstuctor() {
    print('Human.myConstuctor constructor has created');
  }
}