class01 type Operator

class01typeOperator.dart

void main() {
  /// type
  int a = 0;
  double a2 = 0.2;
  
  String b = "b";
  String b2 = "bOb";
  
  bool c = true;
  bool c2 = false;
  
  List d = [];
  List d2 = [1,"2",false];
  List<int> d3 = [1,2,3];
  List<String> d4 = ["4","5","6"];
  print("List index 0 = ${d4[0]}");
  
  Set e = {};
  Set<dynamic> e2 = {1,2,"3"};
  Set<int> e3 = {4,5,6};
  print("Set first = ${e3.first}");
  print("Set -> List index 1 = ${e3.toList()[1]}");
  
  Map f = {};
  Map<String, dynamic> f2 = {"k":1, "k2": "v2"};
  Map<String, int> f3 = {"k":1, "k2":2};
  Map<int, int> f4 = {0:1, 1:2};
  print("Map Key 'k' = ${f3["k"]}");
  print("Map Key 0 = ${f4[0]}");
  
  /// operator
  print( 1 + 1 );
  print( 2 - 2 );
  print( 3 * 3 );
  print( 4 / 2 );
  print( 4 % 3 ); // 나머지
  print( 4 ~/ 3 ); // 몫
  print( null ?? 55 );
  print( true ? 66 : 777 ); 
  print( 0 > 10 );
  print( 0 < 10 );
  print( 2 >= 2 );
  print( 2 <= 3 );
  print( 3 == 3 );
  
  // - spread
  final li = [1,2,3];
  final li2 = [...li, 4,5,6];
  print(li2);
  
  final mapSpread = {"k":1};
  final mapSpreadSum = {...mapSpread, "k2": 2};
  print(mapSpreadSum);
  
  // - addition assignment 더하기 할당
  int value = 1;
  value += 2; // value = value + 2;
  print(value);
  
  value -= 1; // value = value - 1;
  print(value);
  
  value *= 1; // value = value * 1;
  print(value);
  
  // - in(de)crement
  value++;
  print(value);
  value--;
  print(value);
  
  // or / and
  print( value > 0 || value < 100);
  print( value > 0 && value < 2);
  
  //Optional chaining
  Model? model;
  model?.a;
  model?.func();
  
  
}

class Model{
  int a = 0;
  void func() => 1;
}