Range error index invalid value not in range, 0..1 inclusive 2 in dart flutter app

Question

I am following one flutter app tutorial and I encounter this error:

Range error index invalid value not in range, 0..1 inclusive 2

Any suggestions on how I can fix this?

import 'package:flutter/material.dart';

//void main() {
  //runApp(MyApp());
//}
void main()=>runApp(MyApp()); 
class MyApp extends StatefulWidget{

  @override
 State<StatefulWidget> createState(){
   return MyAppState();

 }
}

class MyAppState extends State<MyApp>{

var questionIndex=0;

  void answerQuestion(){
    setState(() {
      questionIndex=questionIndex+1;
    });
   print(questionIndex);
    //print("answer choosen!");
  }
@override
  Widget build(BuildContext context){ 

var questions=['What is your favourite colour','what is favourite animal',];

return MaterialApp(home: Scaffold(
appBar:AppBar(title:Text('my first app'),),
body: Column(children:[Text(questions[questionIndex]),
        //RaisedButton(child: Text("Ansewr 1"), onPressed:()=>print("Answer 1"),),
        //RaisedButton(child: Text("Ansewr 1"),onPressed:answerQuestion),
        RaisedButton(child: Text("Ansewr 0"), onPressed:answerQuestion,),
        RaisedButton(child: Text("Ansewr 1"), onPressed:answerQuestion,),



          ],),

),);
  }
}

Answer 1

I modify your code. Maybe that works for you. And don't use setState() method too much. Try learning bLoc archtecture.

void main() => runApp(MyApp());

class MyApp extends StatefulWidget {
@override
State<StatefulWidget> createState() {
return MyAppState();
 }
}

enum Questions { firstQuestion, secondQuestion }

class MyAppState extends State<MyApp> {
var question = Questions.firstQuestion;

@override
Widget build(BuildContext context) {
var questions = [
  'What is your favourite colour',
  'what is favourite animal',
];

return MaterialApp(
  home: Scaffold(
    appBar: AppBar(
      title: Text('my first app'),
    ),
    body: Column(
      children: [
        Text(questions[question.index]),
        RaisedButton(
          child: Text("Ansewr 0"),
          onPressed: () {
            setState(() {
              question = Questions.firstQuestion;
            });
          },
        ),
        RaisedButton(
          child: Text("Ansewr 1"),
          onPressed: () {
            setState(() {
              question = Questions.secondQuestion;
            });
          },
        ),
      ],
    ),
  ),
);
}
}