dart: Typedef and Class

Typedef

typedef ListOfInts = List<int>; // typescript interface or type like

ListOfInts reverseListOfNumbers(ListOfInts list) {
  var reversed = list.reversed;

  return reversed.toList();
}

Class

late로 constructor 실행시 args 받아서 전역필드에 저장

class Player {
  late final String name;
  late int xp;

  Player(String name, int xp) {
    this.name = name;
    this.xp = xp;
  }

  void sayHello() {
    print('I\'m $name');
  }
}

간단하게

class Player {
  final String name;
  int xp;

// 순차적으로 args 받는다. positional arguments 
  Player(this.name, this.xp);
   

  void sayHello() {
    print('I\'m $name');
  }
}

Named Constructor Parameter !!

class Player {
  final String name;
  int xp;
  String team;
  int age;

  //required 문구 추가 또는 기본값 =
  Player({
    this.name = 'name',
    required this.xp,
    required this.team,
    required this.age,
  });

  void sayHello() {
    print('I\'m $name');
  }
}

void main() {
  var player = Player(
//     name: 'Son',
    xp: 1000,
    team: 'red',
    age: 12,
  );

  print(player.name);

  player.sayHello();
}

Named & positional arguments Constructor
: 의 위치 중요

...


// named 
  Player.createBluePlayer({required String name, required int age})
      : this.age = age,
        this.name = name,
        this.team = 'blue',
        this.xp = 0;
        
 // positional 
 Player.createRedPlayer (String name, int age) 
 	: this.age = age,
        this.name = name,
        this.team = 'red',
        this.xp = 0;
 
        ...
        
void main() {
  var player1 = Player.createRedPlayer(
    'Sonny',
    12,
  );

  var player2 = Player.createBluePlayer(
    name: 'Son',
    age: 12,
  );
}