How to create a button that cycles through the elements of an array?

Question

Java

There are the following elements and their purposes (I won’t give the whole code, I think everything is clear anyway):

private Button next_button;
 private TextView mQuestionTextView;
 private int mCurrentIndex = 0;
 private TrueFalse[] mQuestionBank = new TrueFalse[] {
            new TrueFalse(R.string.question_ocean, true),
            new TrueFalse(R.string.question_mideast, false),
            new TrueFalse(R.string.question_africa, false),
            new TrueFalse(R.string.question_americas, true),
            new TrueFalse(R.string.question_asia, true)
    };

    <b>private void updateQuestion() {
        if (mCurrentIndex != -1) {
            int question = mQuestionBank[mCurrentIndex].getQuestion();
            mQuestionTextView.setText(question);
        } else {
            throw new ArrayIndexOutOfBoundsException("ArrayIndexOutOfBoundException");
            mQuestionTextView.setText(arrayExc);</b>

Далее в методе onCreate это происходит так:
Button mPrevButton = (Button)findViewById(R.id.prevButton);
        mPrevButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v)  {
                    mCurrentIndex = (mCurrentIndex - 1) % mQuestionBank.length;
                    updateQuestion();
                }
        });

Everything works only for an array element > 0, otherwise, of course, an ArrayIndexOutOfBoundsException appears.
(The bold code before my attempts to fix the situation looked like

int question = mQuestionBank[mCurrentIndex].getQuestion();
            mQuestionTextView.setText(question);

, without if/else. in the updateQuestion method.
At the same time, the "Next" button, which cycles through the elements of the array, works cyclically, and there is no exception for going beyond the array:

mNextButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                mCurrentIndex = (mCurrentIndex + 1) % mQuestionBank.length;
                updateQuestion();

The essence of the problem: two buttons using the same methods, but one works in a positive direction normally

mCurrentIndex = (mCurrentIndex + 1) % mQuestionBank.length

; and the other

mCurrentIndex = (mCurrentIndex - 1) % mQuestionBank.length;

does not work.

Answer 1

Everything works only for an array element > 0, otherwise, of course, an ArrayIndexOutOfBoundsException appears

You yourself have pointed out the reason because of which everything falls down.
(mCurrentIndex - 1) % mQuestionBank.length = -1 , with mCurrentIndex = 0
, you can fix prevButton, for example, like this

public void onClick(View v)  {
  mCurrentIndex--;
  if (mCurrentIndex == -1) {
    mCurrentIndex = mQuestionBank.length - 1;
  }
  updateQuestion();
}