CODEWITHSUNDEEP
flutter
AP aul
AP aul

Reputation: 358

How to check SharedPreferences key if not empty or null?

How to check SharedPreferences key if empty or null?

when i run the program it give me an error enter image description here

1.]  Future<String> getStrings() async {
2.]   Future<SharedPreferences> _sPrefs = SharedPreferences.getInstance();
3.]   final SharedPreferences prefs = await _sPrefs;
4.]   appid = prefs.getString('appid');
5.]   print(appid);
6.]   if (appid != '') {
7.]    return appid;
8.]  }
9.] return ''; }

Above is my code, the error is only showing when i run my logout function that has prefs.clear();

Upvotes: 1

Views: 3099

Answers (1)

Richard Heap
Richard Heap

Reputation: 51751

Change (appid != '') to (appid != null). Null and an empty string are different things.

You can shorten this using a null-aware operator to:

return appid ?? '';

Upvotes: 3

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