Why it returns Instance of instead of the value? - dart

Question

Why the getCurrencyFromAPI function returns Intance of currency instead of the value itself. Is there some thing wrong with my model class?
This is the function
import 'dart:convert';
import 'package:app_bloc/data/models/currency.dart';
import 'package:http/http.dart' as http;
import 'package:app_bloc/constants/api_urls.dart';
class Repository {
Future<dynamic> getCurrencyFromAPI() async {
final res = await http.get(Uri.parse(coinbaseURL));
if (res.statusCode == 200) {
final resData = jsonDecode(res.body);
final data = resData['data'] as List;
List<Currency> list = [];
for (var e in data) {
final a = Currency.fromJson(e);
list.add(a);
}
print(list);
} else {
throw Exception('Error fetching data from API');
}
}
}
void main(List<String> args) {
Repository repo = Repository();
repo.getCurrencyFromAPI();
}
this is the model class
class Currency {
String id;
String name;
String minSize;
Currency({required this.id, required this.name, required this.minSize});
factory Currency.fromJson(Map<String, dynamic> data) {
final id = data['id'] as String;
final name = data['name'] as String;
final minSize = data['min_size'] as String;
return Currency(id: id, name: name, minSize: minSize);
}
}

Answer 1

Your Currency class does not have a toString method. That means it inherits the default from Object which returns Instance of 'Currency'.
When you print the List<Currency> it calls toString on every element to get a string representation. So, that's what you see. It is a Currency object.
Try adding:
String toString() => "Currency(id: $id, name: $name, minSize: $minSize)";
to you Currency class and see if it makes a difference.

Answer 2

Currency currencyModelFromJson(String str) => Currency.fromJson(json.decode(str));
class Currency {
String id;
String name;
String minSize;
Currency({required this.id, required this.name, required this.minSize});
factory Currency.fromJson(Map<String, dynamic> data) {
final id = data['id'] as String;
final name = data['name'] as String;
final minSize = data['min_size'] as String;
return Currency(id: id, name: name, minSize: minSize);
}
}
Then do this :
class Repository {
Future<dynamic> getCurrencyFromAPI() async {
final res = await http.get(Uri.parse(coinbaseURL));
if (res.statusCode == 200) {
final resData = jsonDecode(res.body);
final data = resData['data'] as List;
List<Currency> list = [];
for (var e in data) {
final a = currencyModelFromJson(e); // change here
list.add(a);
}
print(list);
} else {
throw Exception('Error fetching data from API');
}
}
}