How should I save string from the Radio Button in arraylist and display it on next page in text box

Question

I am working on Quiz app in which there is a question activity which contains 10 questions. Now the problem is I want to get the selected text on radio button in array and display it on next page in textbox where I am already displaying the correct answer and the question from database

here is the code from first page of radio buttons

List<String> ls = new ArrayList<String>();
    private boolean checkAnswer() {
    String answer = getSelectedAnswer();
    if (answer == null) {
        return false;
    } else {
        ls.add(answer);
        if (currentQ.getAnswer().equalsIgnoreCase(answer)) {
            currentGame.incrementRightAnswers();
        } else {
            currentGame.incrementWrongAnswers();
        }
    return true;
    }
}

/**
 * 
 */
public String getSelectedAnswer() {

    if (c1.isChecked()) {
        return c1.getText().toString();

    }
    if (c2.isChecked()) {
        return c2.getText().toString();
    }
    if (c3.isChecked()) {
        return c3.getText().toString();
    }
    if (c4.isChecked()) {
        return c4.getText().toString();
    }

    return null;
}

@Override
public void onCheckedChanged(RadioGroup group, int checkedId) {
    // TODO Auto-generated method stub
    // Log.d("Questions", "Moving to next question");
    a++;
    qno++;

    if (!checkAnswer())
        return;

    if (currentGame.isGameOver()) {
        // stoptime();
        db.open();
        String total = currentGame.getRight() + "";
        db.insertOptions(topic1, total, mon);
        db.close();
        alertb();
        // mCountDown.cancel();
        a = 0;
        qno = 1;

    } else {
        Intent i = new Intent(this, QuestionActivity.class);

        startActivity(i);
        finish();
    }
}

public String show(int i) {
    String a = ls.get(i);
    return a;
}

In my checkanswer() I am adding the text of radio button in list ls.add(Item). but here I am making some mistake please correct me

I have written show() on above page which would help me to get elements of arraylist on next page here is my code on next page

public static String getAnswers(List<Question> questions) {
        int question = 1;
        StringBuffer sb = new StringBuffer();


        for (Question q : questions){


            sb.append("Q").append(question).append(") ").append(q.getQuestion()).append("? \n");
            sb.append("Your Answer: ").append(qa.show(question)).append("\n");
            sb.append("Correct Answer: ").append(q.getAnswer()).append("\n");

            sb.append("____________________________________________________________________________________").append("\n\n");
            question ++;
        }

From this page my correct answer and Questions are being displayed but the answer which I am selecting is not working

It gives me error as"array index out of bound no element at position 1" please help me

Answer 1

Data members loose all values when the activity class gets killed in android. Hence, you are getting IOOBE while accessing the list values declared in your previous activity. Create a bundle and add the following code in your previous activity's onDestroy method

Bundle b = new Bundle();
b.putStringArrayList("answers", ls);

set this bundle to the intent that you use to start new activity

Intent i = new Intent(this, QuestionActivity.class);
i.setExtra(b)

In your other activity's onCreate function use the following code :

Bundle bundle = getExtras();
List<String> tmp = bundle.getStringArrayList("answers")

Now you will get all the data that was loaded into last activity's list variable.

If you have mapping in between your questions and answers list then loop with a temp variable and use it as index to your lists to get corresponding mapped data members. Also, start from 0.