Why local storage enables offline data in Flutter - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to save a string value to local storage using Flutter's SharedPreferences.

Flutter

final prefs = await SharedPreferences.getInstance();
await prefs.setString('username', [1]);

Drag options to blanks, or click blank then click option'

AJohnDoe

B"JohnDoe"

C12345

Dtrue

Attempts:

3 left

💡 Hint

Common Mistakes

Forgetting to put quotes around the string value.

Passing a variable name without quotes if it's not defined.

You must provide the string value in quotes to save it correctly.

2fill in blank

medium

Complete the code to read a string value from local storage using Flutter's SharedPreferences.

Flutter

final prefs = await SharedPreferences.getInstance();
String? username = prefs.[1]('username');

Drag options to blanks, or click blank then click option'

AgetString

Bremove

CsetString

DgetInt

Attempts:

3 left

💡 Hint

Common Mistakes

Using setString instead of getString when reading data.

Using getInt when the stored value is a string.

Use getString to retrieve a string value from SharedPreferences.

3fill in blank

hard

Fix the error in the code to check if local storage has a key before reading it.

Flutter

final prefs = await SharedPreferences.getInstance();
if (prefs.[1]('username')) {
  String? username = prefs.getString('username');
}

Drag options to blanks, or click blank then click option'

AhasKey

Bexists

CcheckKey

DcontainsKey

Attempts:

3 left

💡 Hint

Common Mistakes

Using hasKey or exists which do not exist in SharedPreferences.

Trying to read a key without checking if it exists.

The correct method to check if a key exists in SharedPreferences is containsKey.

4fill in blank

hard

Fill both blanks to save and then read an integer value from local storage.

Flutter

final prefs = await SharedPreferences.getInstance();
await prefs.[1]('counter', 10);
int? counter = prefs.[2]('counter');

Drag options to blanks, or click blank then click option'

AsetInt

BgetString

CgetInt

DsetString

Attempts:

3 left

💡 Hint

Common Mistakes

Using setString or getString for integer values.

Mixing up the order of saving and reading methods.

Use setInt to save an integer and getInt to read it back.

5fill in blank

hard

Fill both blanks to remove a key from local storage and check if it still exists.

Flutter

final prefs = await SharedPreferences.getInstance();
await prefs.[1]('session');
bool exists = prefs.[2]('session');
print('Session key exists: ' + exists.toString());

Drag options to blanks, or click blank then click option'

Aremove

BcontainsKey

CgetBool

Dclear

Attempts:

3 left

💡 Hint

Common Mistakes

Using clear which deletes all keys instead of remove.

Using getBool to check if a key exists.

Use remove to delete a key, containsKey to check if it exists.