Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

When there is no data. I am getting this error, please help to solve this. #1

Closed
PramodBhai-PK opened this issue Apr 22, 2021 · 1 comment

Comments

@PramodBhai-PK
Copy link

I am using the ternary operator but it is throwing an error. please help me. I want to show No quiz data when there is no data available.

Capturem

E/flutter ( 7649): [ERROR:flutter/lib/ui/ui_dart_state.cc(166)] Unhandled Exception: RangeError (index): Invalid value: Valid value range is empty: 0
E/flutter ( 7649): #0 List.[] (dart:core-patch/growable_array.dart:166:60)
E/flutter ( 7649): #1 _QuizState.getQuestions (package:myquiz/screens/quiz.dart:48:33)
E/flutter ( 7649):
E/flutter ( 7649): #2 _QuizState.initState (package:myquiz/screens/quiz.dart:33:10)
E/flutter ( 7649): #3 StatefulElement._firstBuild (package:flutter/src/widgets/framework.dart:4684:58)
E/flutter ( 7649): #4 ComponentElement.mount (package:flutter/src/widgets/framework.dart:4520:5)
E/flutter ( 7649): #5 Element.inflateWidget (package:flutter/src/widgets/framework.dart:3490:14)
E/flutter ( 7649): #6 Element.updateChild (package:flutter/src/widgets/framework.dart:3258:18)
E/flutter ( 7649): #7 SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:5874:14)
E/flutter ( 7649): #8 Element.inflateWidget (package:flutter/src/widgets/framework.dart:3490:14)
E/flutter ( 7649): #9 Element.updateChild (package:flutter/src/widgets/framework.dart:3258:18)
E/flutter ( 7649): #10 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:4571:16)
E/flutter ( 7649): #11 Element.rebuild (package:flutter/src/widgets/framework.dart:4262:5)
E/flutter ( 7649): #12 ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:4525:5)
E/flutter ( 7649): #13 ComponentElement.mount (package:flutter/src/widgets/framework.dart:4520:5)
E/flutter ( 7649): #14 Element.inflateWidget (package:flutter/src/widgets/framework.dart:3490:14)
E/flutter ( 7649): #15 Element.updateChild (package:flutter/src/widgets/framework.dart:3258:18)
E/flutter ( 7649): #16 SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:5874:14)
E/flutter ( 7649): #17 Element.inflateWidget (package:flutter/src/widgets/framework.dart:3490:14)
E/flutter ( 7649): #18 Element.updateChild (package:flutter/src/widgets/framework.dart:3258:18)
E/flutter ( 7649): #19 SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:5874:14)
E/flutter ( 7649): #20 Element.inflateWidget (package:flutter/src/widgets/framework.dart:3490:14)
E/flutter ( 7649): #21 Element.updateChild (package:flutter/src/widgets/framework.dart:3258:18)
E/flutter ( 7649): #22 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:4571:16)
E/flutter ( 7649): #23 StatefulElement.performRebuild (package:flutter/src/widgets/framework.dart:4719:11)
E/flutter ( 7649): #24 Element.rebuild (package:flutter/src/widgets/framework.dart:4262:5)
E/flutter ( 7649): #25 ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:4525:5)
E/flutter ( 7649): #26 StatefulElement._firstBuild (package:flutter/src/widgets/framework.dart:4710:11)
E/flutter ( 7649): #27 ComponentElement.mount (package:flutter/src/widgets/framework.dart:4520:5)
E/flutter ( 7649): #28 Element.inflateWidget (package:flutter/src/widgets/framework.dart:3490:14)
E/flutter ( 7649): #29 Element.updateChild (package:flutter/src/widgets/framework.dart:3258:18)
E/flutter ( 7649): #30 SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:5874:14)
E/flutter ( 7649): #31 Element.inflateWidget (package:flutter/src/widgets/framework.dart:3490:14)
E/flutter ( 7649): #32 Element.updateChild (package:flutter/src/widgets/framework.dart:3258:18)
E/flutter ( 7649): #33 SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:5874:14)
E/flutter ( 7649): #34 Element.inflateWidget (package:flutter/src/widgets/framework.dart:3490:14)
E/flutter ( 7649): #35 Element.updateChild (package:flutter/src/widgets/framework.dart:3258:18)
E/flutter ( 7649): #36 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:4571:16)
E/flutter ( 7649): #37 StatefulElement.performRebuild (package:flutter/src/widgets/framework.dart:4719:11)
E/flutter ( 7649): #38 Element.rebuild (package:flutter/src/widgets/framework.dart:4262:5)
E/flutter ( 7649): #39 ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:4525:5)
E/flutter ( 7649): #40 StatefulElement._firstBuild (package:flutter/src/widgets/framework.dart:4710:11)
E/flutter ( 7649): #41 ComponentElement.mount (package:flutter/src/widgets/framework.dart:4520:5)
E/flutter ( 7649): #42 Element.inflateWidget (package:flutter/src/widgets/framework.dart:3490:14)
E/flutter ( 7649): #43 Element.updateChild (package:flutter/src/widgets/framework.dart:3258:18)
E/flutter ( 7649): #44 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:4571:16)
E/flutter ( 7649): #45 Element.rebuild (package:flutter/src/widgets/framework.dart:4262:5)
E/flutter ( 7649): #46

@feMoraes0
Copy link
Owner

feMoraes0 commented Apr 22, 2021

Hello @PramodBhai-PK, checking length property documentation (https://api.dart.dev/stable/2.12.4/dart-core/List/length.html) you will find the return type as int, so you couldn't check with null. In my original code I had already checked if there are questions in my list to render the component. So, if you want to check if the list is empty, you should check if questions.length is equal zero (do it after a check if questions already exists otherwise you will receive another error).

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Labels
None yet
Projects
None yet
Development

No branches or pull requests

2 participants