dart 3.0 _ pattern matching

readme.md

dart 3.0 _ pattern matching

Created with <3 with dartpad.dev.

main.dart

// pattern matching

void main() {
  //validation
  
  final user = ('miro', 30);
  
  // build time 이 아닌 runtime에서 error 나게 할수 있음
  final (name as String, age as int) = user;
//   final (name as int, age as int) = user;
  
  print(name);
  print(age);
  
  print('----------------');
  
  switcher(['1', '2']);
  switcher([1, 2]);
  switcher([1, 2, 3]);
  switcher(['1', '2', '3']);
  switcher([1, '2']);
  
  print('----------------');
  print(switcher2(5, true));
  print(switcher2(7, true));
  print(switcher2(7, false));
  
  print('----------------');
  ifMatcher();
  
  
}


void switcher(dynamic gg){
  switch(gg){
    case 'aa':
      print('match aa');
      case ['1', '2']:
      print('match [1, 2]');
      
      // 3개가 들어간 어떤 list 도 다 잡아
    case [_, _, _]:
      print('match [_, _, _]');
    case [int a, int b]:
      print('match [int $a, int $b]');
      
//       조건도가능
//     case <10 && > 5:
//       print('match <10 && > 5 ');
    default:
      print('no match');
  }
}


String switcher2(dynamic val, bool condition) => switch(val){
    5 => 'match 5',
    7 when condition => 'match 7 and true',
    _ => 'no match',
};




void ifMatcher(){
  final user ={
    'name': 'miro',
    'age' : 10,
  };
  
  if(user case {'name': String name, 'age': int age}){
    print(name);
    print(age);
  }
}