Flutter: Constructors

// All about class construtor and how to use this.
void main(){
  
  Human jenny = Human(height: 15, weight: 3.4);
  
  //jenny.talk('Mommy');
  
  print(jenny.height);
  print(jenny.weight);
  
  Human james = Human(height: 20, weight: 4.2);
  print(james.height);
  print(james.weight);
  
  
//   Human james = Human(20);
  
//   print(james.height);

}

class Human {
  
  double height;
  double weight;
  int age = 0;
  
 Human({this.height, this.weight});
  
  //        or
  
//   Human({double height, double weight}){
//     this.height = height;
//     this.weight = weight;
//   }
  
  void talk(String whatToSay){
    print(whatToSay);
  }
}