8. Dart - Inheritance Classes

 Make a default class:

class User {

    String username;

    int age;

    void printmyinfo() {

        print('$username is $age years old');

    }

    User(this.username, this.age); // constructor

}

Make a inheritance class (inherits all stuff from class above but has extra stuff):

// need to create a super constructor if the extension target class has a constructor

class UserBoss extends User {

    UserBoss(String a, int b) : super(a,b); // must be same as the variable declared in UserBoss

    // "super" is a constructor that changes the extension target classes' property

    // aand bare property variable of the UserBoss class and similar for User class

    void printbossstuff() {

        print('boss stuff');

    }

}