How to Print instance in Flutter/Dart? [duplicate] - json

Question

This question already has answers here:
Default stringify for objects, equivalent to Java's toString?
(3 answers)
Closed 1 year ago.
I have one data type Map<String,CartItem> _items = {};
And using print(_items)
And the output is:
{
p1: Instance of 'CartItem',
p2: Instance of 'CartItem'
}
Is there any method by which I can see the full logs(values) of CartItem? as my expectation is:
{
p1: some json formatted structure,
p2: some json formatted structure
}
class CartItem {
final String id;
final String title;
CartItem({
#required this.id,
#required this.title,
});
}

Answer 1

You just need to override your toString method:
class CartItem {
final String id;
final String title;
CartItem({
required this.id,
required this.title,
});
#override
String toString() {
return '{id: $id, title: $title}';
}
}
Usage:
main() async {
CartItem item = CartItem(id: '1', title: 'title');
print(item); // {id: 1, title: title}
Map<String, CartItem> items = {
'p1': CartItem(id: '1', title: 'title'),
'p2': CartItem(id: '2', title: 'titl2'),
};
print(items); // {p1: {id: 1, title: title}, p2: {id: 2, title: titl2}}
List<CartItem> list = [
CartItem(id: '1', title: 'title'),
CartItem(id: '2', title: 'title2'),
];
print(list); // [{id: 1, title: title}, {id: 2, title: title2}]
}

Answer 2

You have to loop through the items to get their specific values and not their instances.
_items.forEach((item) {
print('id: ${item.id}, title: ${item.title}');
});