LateInitializationError: Field 'ques' has not been initialized - flutter

Question

It shows this error although I have added late and required in the Question class constructor. It's repeatedly shows
Exception caught by widgets library
The following LateError was thrown building _BodyBuilder:
LateInitializationError: Field 'ques' has not been initialized
Main class:
import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'QuestionsAnswers.dart';
void main() {
runApp(const Quizzler());
}
class Quizzler extends StatelessWidget {
const Quizzler({Key? key}) : super(key: key);
#override
Widget build(BuildContext context) {
return MaterialApp(
debugShowCheckedModeBanner: false,
home: SafeArea(
child: Scaffold(
backgroundColor: Colors.black,
appBar: AppBar(
backgroundColor: Colors.grey[900],
leading: Icon(Icons.games),
title: Text(
'Quizzler',
style: TextStyle(
fontSize: 20.0,
fontWeight: FontWeight.bold,
fontStyle: FontStyle.italic,
color: Colors.white,
),
),
),
body: QuizPlay(),
),
),
);
}
}
class QuizPlay extends StatefulWidget {
const QuizPlay({Key? key}) : super(key: key);
#override
State<QuizPlay> createState() => _QuizplayState();
}
class _QuizplayState extends State<QuizPlay> {
List<Icon> score=[];// array of score icon
List<Questions>questionsAndAnswers=[
Questions(a:'Pakistan is an under developed country',b:true),
Questions(a:'Imran Khan is the Prime Minister of Pakistan',b:true),
Questions(a:'Y comes after U',b:false)
];
int questiontracker=0;// variable to increment of questions
#override
Widget build(BuildContext context) {
return Column(
crossAxisAlignment: CrossAxisAlignment.stretch,
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: [
Expanded(
flex: 4,
child: Padding(
padding: EdgeInsets.all(10.0),
child: Center(
child: Text(
questionsAndAnswers[questiontracker].ques,
style: TextStyle(
fontSize: 25.0,
color: Colors.white70,
),
),
),
),
),
Expanded(
child: Padding(
padding: EdgeInsets.all(10.0),
child: ElevatedButton(
style: ButtonStyle(
backgroundColor: MaterialStateProperty.all(Colors.green),
),
onPressed: () {
//Yes button
bool answer=questionsAndAnswers[questiontracker].ans;
if (answer==true)
{
print('correct answer');
}
else
{
print('wrong answer ');
}
setState(() {
questiontracker++;
score.add(Icon(Icons.check,color: Colors.green,)) ;
});
},
child: Text(
'Yes',
style: TextStyle(
fontSize: 20.0,
),
),
),
),
),
Expanded(
child: Padding(
padding: EdgeInsets.all(10.0),
child: ElevatedButton(
style: ButtonStyle(
backgroundColor: MaterialStateProperty.all(Colors.red),
),
onPressed: () {
// No button
bool answer=questionsAndAnswers[questiontracker].ans;
if (answer==false)
{
print('correct answer');
}
else
{
print('wrong answer ');
}
setState(() {
questiontracker++;
score.add(Icon(Icons.close,color: Colors.red,)) ;
});
},
child: Text(
'No',
style: TextStyle(
fontSize: 20.0,
),
),
),
),
),
Row(
children: score,
),
],
);
}
}
###Question CLASS###
class Questions{
late String ques;
late bool ans;
Questions({required String a,required bool b})
{
a=ques;
b=ans;
}
}

Answer 1

make it
ques = a;
ans = b;
This stores the value on the right in the value on the left.

Answer 2

Your class constructor Questions is wrong, change it to:
class Questions{
late String ques;
late bool ans;
Questions({required String a,required bool b}) {
ques = a;
and = b;
}
}

Answer 3

What is the purpose of having your questions as a plain class? I'd suggest turning it into a module class which in turn should be
class Question
{
String? ques;
bool? ans;
Question({
this.ques, this.ans});
}
and when you want to initialize a question I'd suggest creating a list
List<Question> questions = [];
question.add(Question("question",true));
// add more as you wish
This will allow you to turn it into JSON which will enable you to maybe provide questions from an online database to the app without needing to update the app every time you want to add a question.