APref | Android easy shared preferences with preference model holder | Database library

public class Quiz_adapter extends RecyclerView.Adapter {
private final Context mCtx;
private final List quizList;
public Quiz_adapter(Context mCtx, List quizList) {
    this.mCtx = mCtx;
    this.quizList = quizList;
}

@NotNull
@Override
public Quiz_adapter.QuizViewHolder onCreateViewHolder(@NotNull ViewGroup parent, int viewType) {
    LayoutInflater inflater = LayoutInflater.from(mCtx);
    @SuppressLint("InflateParams") View view = inflater.inflate(R.layout.cardview_quiz, null,false);
    view.setLayoutParams(new RecyclerView.LayoutParams(RecyclerView.LayoutParams.MATCH_PARENT, RecyclerView.LayoutParams.WRAP_CONTENT));
    return new Quiz_adapter.QuizViewHolder(view);
}
@Override
public void onBindViewHolder(QuizViewHolder holder, int position) {
    Quiz quiz = quizList.get(position);
    holder.txtquestion.setText(quiz.getQn());
    holder.rb_option1.setText(quiz.getOpt1());
    holder.rb_option2.setText(quiz.getOpt2());
    if(quiz.getOpt3().equals("")){
        holder.rb_option3.setVisibility(View.GONE);
    }else{
        holder.rb_option3.setText(quiz.getOpt3());
    }
    if(quiz.getOpt4().equals("")){
        holder.rb_option4.setVisibility(View.GONE);
    }else{
        holder.rb_option4.setText(quiz.getOpt4());
    }
    holder.rg_option.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
        @Override
        public void onCheckedChanged(RadioGroup radioGroup, int i) {
                //int radio =  radioGroup.getCheckedRadioButtonId();
            if (radioGroup.getCheckedRadioButtonId() == -1)
            {
                // no radio buttons are checked
                Toast.makeText(mCtx,"No Option is selected", Toast.LENGTH_SHORT).show();
            }
            else
            {
                if(i == R.id.rb_option1){
                    quiz.setAns(1);
                    notifyDataSetChanged();
                }if(i == R.id.rb_option2){
                    quiz.setAns(2);
                    notifyDataSetChanged();
                }if(i == R.id.rb_option3){
                    quiz.setAns(3);
                    notifyDataSetChanged();
                }if(i == R.id.rb_option4){
                    quiz.setAns(4);
                    notifyDataSetChanged();
                }
                // one of the radio buttons is checked
                Quiz quiz1=new Quiz(quiz.getId(),quiz.getQn(),quiz.getOpt1(),quiz.getOpt2(),quiz.getOpt3(),quiz.getOpt4(),quiz.getAns());
        //here I am storing answer in shared preference to send on server.
                Apref.getInstance(mCtx).addUpdateShoppingCartList(quiz1);
            }
        }
    });
}
@Override
public int getItemCount() {
    return quizList.size();
}

public static class QuizViewHolder extends RecyclerView.ViewHolder {

    TextView txtquestion;
    RadioGroup rg_option;
    RadioButton rb_option1,rb_option2,rb_option3,rb_option4;
    RelativeLayout llquiz;

    QuizViewHolder(View itemView) {
        super(itemView);
        llquiz=itemView.findViewById(R.id.llquiz);
        txtquestion=itemView.findViewById(R.id.txtquestion);
        rg_option = itemView.findViewById(R.id.rg_option);
        rb_option1 = itemView.findViewById(R.id.rb_option1);
        rb_option2 = itemView.findViewById(R.id.rb_option2);
        rb_option3 = itemView.findViewById(R.id.rb_option3);
        rb_option4 = itemView.findViewById(R.id.rb_option4);
    }
}
}