Small file demonstrating basic Dart language features. Made for a workshop I did about Flutter.

dart_demo.dart

import 'dart:math';

class Person {
  String firstName;
  String lastName;
  String _favoriteColor;
  String hobby;

  set favoriteColor(String newFavorite) {
    print("My favorite color has changed from $_favoriteColor to $newFavorite");
    _favoriteColor = newFavorite;
  }

  Person(this.firstName, this.lastName, this._favoriteColor, {this.hobby});

  void sayHello() {
    print("Hi, I'm $firstName" + (lastName != null ? " $lastName" : ""));
    print("My favorite color is $_favoriteColor, and I like $hobby");
  }

  static void sayGoodbyeTo(String otherPerson) => print("Bye, $otherPerson!");

  void countToFive() async {
    for (int i = 1; i < 6; i++) {
      print(i);
      await Future.delayed(Duration(seconds: 1));
    }
  }

  void sayLetters() {
    Future.forEach([' a', ' b', ' c', ' d', ' e'], (letter) async {
      print(letter);
      await Future.delayed(Duration(seconds: 1));
    });
  }
}

void main() {
  final john = Person("John", "Geller", "blue", hobby: "reading");
  john.sayHello();

//  john.favoriteColor = "red";

//  john.countToFive();
//  john.sayLetters();

  //////////////////////////////////////////////////////////////////////////////

//  [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
//      .map((num) => num * 7)
//      .where((num) => num % 5 == 0)
//      .forEach((num) => print(num));

  //////////////////////////////////////////////////////////////////////////////

//  final sam = Random().nextBool() ? Person("sam", "johnson", "green") : null;
//
//  print("Sam's favorite hobby is ${sam?.hobby ?? "unknown"}");
}