import 'dart:convert';

void main(){

//1.List转为String
  var list = <String>['a', 'b'];
  String s = JsonEncoder().convert(list); 
  print(s);

//2.String转回List
  List<String> list1 = <String>[];
  for (var value in JsonDecoder().convert(s)) {
    print(value);
    list1.add(value);
  };
  list1.forEach(print);
}