CODEWITHSUNDEEP
javaandroideclipseimagebuttonindexoutofboundsexception
user2440001
user2440001

Reputation: 1

ArrayIndexOutOfBoundsException in android application

I have an ArrayIndexOutofBounds exception in my application. I want to put a previous button in my app. I have 5 elements in my array the button cycles through. How do I make it so when user hits element[0], it will loop back to element[4] and not go to a [-1] causing the exception?

My code is as follows:

mPrevButton = (ImageButton)findViewById(R.id.prev_button);
mPrevButton.setOnClickListener (new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        mCurrentIndex = (mCurrentIndex - 1) % mQuestionBank.length;
        mIsCheater = false;
        updateQuestion();
    }
}

What is the proper way of doing this:

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

Upvotes: 0

Views: 361

Answers (2)

cdr89
cdr89

Reputation: 986

Try to increment in this way:

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

Upvotes: 5

Adrian Adamczyk
Adrian Adamczyk

Reputation: 3080

Keep it simple?

if (mCurrentIndex > 0)
    mCurrentIndex--;
else
    mCurrentIndex = mQuestionBank.length-1;

Upvotes: 5

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