Learning Dart [Basic]

/* Basic Dart
 * https://www.tutorialspoint.com/dart_programming/dart_programming_functions.htm
 * https://dartpad.dartlang.org/
 */

void main() {
  int _int, __int;
  String _string;

  /*
   * Data Type
   * 1. Numbers
   *    - int
   *    - double
   * 2. Strings
   *    - Runes (UTF-32)
   *    -   String (UTF-16)
   * 3. Boolean
   *    - bool
   * 4. List & Map
   *    - List (ordered group of objects)
   *    - Map (represent set of values as key-value pairs)
   * 5. Dynamic Type
   *    - dynamic (if data type not specified || explicitly used)
   */

  /*
   * const = compile-time constant (Implicitly final)
   */

  // ~/ division (return int)
  print("/ = ");
  print(25 / 4);
  print("");
  print("~/ = ");
  print(25 ~/ 4);
  print("");

  /*
   * is = true if object has specified type
   * is! = false if object has specified type
   */
  _int = 5;
  if (_int is int) {
    print("_int is int");
  }

  if (_int is! String) {
    print("_int is not String");
  }
  print("");

  /*
   * expr1 ?? expr2
   * (if expr1 is !NULL then return expr1 else return expr2)
   */
  _int = null;
  __int = 5;
  print(_int ?? __int);
  print("");

  /*
   * Parsing
   *    - parse()
   * parse a string into a number
   */
  _string = "123";
  print(num.parse(_string) + 32);
  print("");

  /*
   * String
   *    - Single line vs Multi line
   */
  _string = 'Single line';
  print("Current String = ${_string}");
  _string = "Single line";
  print("Current String = ${_string}");
  _string = '''Multi
  line''';
  print("Current String = ${_string}");
  _string = """Multi
    line""";
  print("Current String = ${_string}");

  print("");

  /*
   * List
   *    - Fixed Length
   *    - Growable
   */
  List listAnimals = new List(5);
  listAnimals[0] = "Dog";
  listAnimals[1] = "Cat";
  listAnimals[2] = "Sheep";
  listAnimals[3] = "Lizard";
  listAnimals[4] = "Bear";
  print("List of Animals = ${listAnimals}");

  List listDogs = new List();
  listDogs.add("Beagle");
  listDogs.add("Pitbull");
  listDogs.add("Bull Dog");
  listDogs.add("Chihuahua");
  listDogs.remove("Bull Dog");
  listDogs.removeAt(0);
  print("List of Dogs = ${listDogs}");
  print("");

  /*
   * Maps
   */
  Map profile = new Map();
  profile = {'Name': 'John Doe', 'Password': 'jonjon'};
  profile['Description'] = 'Looks like a dead body';
  print("Profile: ${profile['Description']}");
  print("");

  /*
   * Symbol
   */

  /*
   * Runes
   */
  Runes _runes = new Runes('\u{1f605}');
  print("Runes: ${new String.fromCharCodes(_runes)}");

  /*
   * Function
   *    - [] = optional parameter
   *    - {} = optional named parameter
   */
  foo("Hello");
  optionalNamed(myString: "World");
  optionalNamed();
  // Lambada Function / Arrow Function
  lambadaFun();
}

foo(String _string, [int _int]) {
  print(_string);
  print(_int);
}

optionalNamed({String myString : "Default Value"}) {
  print(myString);
}

lambadaFun() => print("This is lambada");