Box and put/get
- Flutter course
- Advanced
- Lesson 12/69
- 4 min
Learn put and get on a Hive box.
put and get
You store a value with box.put('key', value) and read it with box.get('key'). The key is always a string; the value can be anything from primitive types to lists and maps. put is an asynchronous operation.
await box.put('theme', 'dark');
final theme = box.get('theme');Default value
If the key is not in the box, get returns null. You handle this safely with the defaultValue parameter. This is useful when settings have not been saved yet on first app launch.
final theme = box.get('theme', defaultValue: 'light');Practice Store and read a value
Open a box named 'settings'. Put 'dark' under the key 'theme'. Read the value with the same key and print it.
Starter code
import 'package:hive/hive.dart';
void main() async {
Hive.init('hive_data');
final box = await Hive.openBox('settings');
// 'theme' anahtarına 'dark' değerini koy
// 'theme' değerini yazdır
await box.close();
}Sample solution
import 'package:hive/hive.dart';
void main() async {
Hive.init('hive_data');
final box = await Hive.openBox('settings');
await box.put('theme', 'dark');
print(box.get('theme'));
await box.close();
}Expected output
dark
Questions and answers
Review the lesson questions together with their answers. To test yourself, solve the lesson interactively.
1 What does box.get('theme') return if the key is not in the box?
- 0
- Empty string
- Throws an error
- null Correct answer
Explanation: If the key is missing, get returns null by default; if defaultValue is provided, it returns that.
2 Store a value
await box.____;await box.put('theme', 'dark');Explanation: To store a value you use put; the first parameter is the key, the second is the value.
3 put and get parts
| Term | Meaning |
|---|---|
put |
Stores a value |
get |
Reads a value |
defaultValue |
Returned when key is missing |
delete |
Deletes a value |